Most of the research on Ultraviolet (UV) radiation are based on the reanalysis data or atmospheric model data due to the limitation of observation altitude and the lack of the observation data in the near space. These methods lead to a fact that UV radiation research are highly susceptible to extremes in atmospheric constituent concentrations. Meanwhile, the analysis results are delayed and do not meet the timeliness needs of related applied research. So, the research of the change in UV radiation and influencing elements are analyzed which use the Chinese region as an example. Ozone is the most dominant source of OH in the near space. The photochemical reactions of both are controlled by the UV radiation. The photochemical relationship between OH and ozone and the principle of direct and indirect modification of ultraviolet radiation by photochemical action are the research bases in the near space.In this study, the GEOS-Chem model is used to simulate the distribution of monthly mean OH and ozone concentrations from 0 to 80 km altitude with a horizontal resolution of 2°×2.5° in China. The MERRA-2 reanalysis data is used as the meteorological data. The default emission data are configured by the HEMCO module. The relationships of concentration changing between OH and ozone are summarized under the simulated conditions which are close to the actual atmospheric environment. On the one hand, a negative correlation is shown between OH and ozone concentration due to the steady state properties of the near space itself and the influence on the photolysis of ozone by UV radiation. For example, the region of high OH concentration decreases gradually with increasing latitude in summer. While the characteristics of high ozone concentration is in contrast to the OH features. On the other hand, the complex deviating radiative equilibrium state of near space itself and its sensitivity to external forcing perturbations lead to a positive correlation between OH and ozone concentration. These phenomena are inconsistent with the theory. For instance, the high values of OH and ozone concentrations in winter occur in the south-western region simultaneously. These results indicate that the relationship between the changes of OH and ozone concentration are both regularity and complexity. The changes in ozone concentration, which is influenced by OH, alter the irradiance in the UV-B band. The TUV radiation transfer model is used to simulate and calculate the radiation. The results of TUV show the monthly variation conditions of irradiance at different representative altitudes and reveal that the irradiance varies widely which is from 3.43 W·m-2 to 16.15 W·m-2 from 22 km to 42 km. The minimum value is at 22 km in the northwest region in May. The maximum irradiance is at 42 km in the Central and South China region in January. The irradiance exhibits a combination of bimodal and oscillatory characteristics in North China, Central and South China, South China Sea region and other region. The maximum and minimum of irradiance appear in different months depending on the regions. However, the maximum value occurs in November and the minimum value appears in May mostly. Besides, the maximum annual difference of irradiance is at 32 km for different region. The maximum annual difference of irradiance is 2.29 W·m-2 in the North China region, while the minimum annual difference of irradiance is 0.53 W·m-2 at 42 km in the South China sea region. The irradiance has the most dramatic change at the 22 km, which is from 2.42% to 32.79%.These variations mean that there are great differences in the impact and effect of ultraviolet radiation on astrobiology, aircraft materials and some others in different regions, altitudes and periods. The targeted considerations are necessary in the program design and analysis of the results in the related study areas.

Underwater Wireless Optical Communication (UWOC) capitalizes on the blue-green segment of the light spectrum which is subject to minimal attenuation in marine environments, thereby rendering it optimal for the conveyance of information. The advantages of UWOC are manifold, it boasts of swift data transmission, negligible latency, and fortified confidentiality. However, UWOC grapples with significant barriers which encompass the limitation of transmission range and the deleterious effects attributable to the intrinsic properties of seawater, as well as marine turbulence-factors like absorption, scattering, bubbles and turbulence that collectively compromise communicative efficiency. To systematically confront these impediments and to gauge the comprehensive influence of the aforementioned factors on UWOC system efficacy, this inquiry has formulated an integrative underwater wireless optical channel model. This archetype not only encapsulates solitary influences but also their concomitant interactions and aggregate impact on signal transmission. By harnessing the Mie scattering theorem, the research meticulously delineates the volume scattering function, the scattering coefficient, and the phase function of microbubble assemblages in seawater—pivotal determinants essential for the assessment of scattering phenomena on the propagation of optical signals. Addressing turbulence, an elaborate channel model featuring a mixed exponential generalized Gamma distribution is employed, defining the statistical behavior of turbulence to faithfully represent the stochastic and unpredictable nature of the channel. This study extends its analysis to include the repercussion of signal attenuation and acoustic noise as a consequence of turbulence, effectively projecting these perturbations onto the optical signals disseminated through the composite channel. Importantly, it elucidates a closed-form expression for the Bit Error Ratio (BER) within the composite channel, employing On-Off Keying (OOK) modulation, thus establishing a theoretical groundwork for the analysis of UWOC system performance. The research delves into the impact of critical determinants such as turbulence strength, bubble density, transmission range, and marine water quality on the BER metrics of UWOC systems. It is discerned that heightened turbulence intensity incrementally necessitates a greater minimum Signal to Noise Ratio (SNR) at the receiver end to maintain a predetermined average BER. Consistent with this SNR, an augmentation in turbulence intensity conspicuously degrades system throughput, inducing a systematic deterioration in BER performance. Within a transparent seawater milieu at a transmission span of 20 m, with a bubble concentration of 3×106 per cubic volume, the system's mean BER is recorded at 4.57×10-4. As the bubble density escalates to 9×106 and subsequently to 9×107 per cubic volume, the average BER correspondingly declines to 5.76×10-4 and 1.19×10-2. In scenarios of turbulence characterized by a scintillation index of 1.932 8, the system is adept at sustaining low BER transmissions. Ensuring dependable communication quality with an average BER falling below 10-3 across an array of aquatic environments—be it crystalline seawater, littoral waters, or murky harbor waters—the utmost permissible transmission distances with bubble presence (at a density of 1×107 per cubic volume) are confined to 22.5 m, 10.4 m, and 2.3 m respectively. Absent bubble interference, these distances are extendable to 28.0 m, 13.5 m, and 2.7 m. Given the pronounced absorption and scattering induced by elevated turbidity and suspended particulates, securing long-range communication in silt-laden harbor waters presents a significant hurdle. Additionally, the study substantiates that elevating the link distance precipitates an almost linear augmentation in BER, indicative of a noteworthy degeneration in signal integrity. The outcomes not only underscore the exigency of crafting and fine-tuning UWOC systems attuned to the vicissitudes of the oceanic realm but also accentuate the latent efficacy of modulation methodologies and channel coding strategies as instrumental in amplifying system competence.

The optical signal is easy to be absorbed and scattered during transmission with Underwater Optical Wireless Communication (UWOC) technology, resulting in serious optical power attenuation and further affecting the signal quality. In order to realize long-distance data transmission, it is very important to recognize, enhance and extract weak light signal under low Signal-to-Noise Ratio (SNR). Stochastic resonance produces synergistic effect through nonlinear system, weak driving signal and appropriate amount of noise under certain conditions, which not only improves the output signal-to-noise ratio, but also detects useful signals. However, the current parameter selection of stochastic resonance system depends on artificial setting, which is not flexible enough to give full play to the advantages of stochastic resonance signal detection. In this paper, an adaptive stochastic resonance detection scheme based on multi-strategy fusion particle swarm optimization is proposed by analyzing the characteristics of weak underwater light signals and the conditions of stochastic resonance generation. It solves the problem that traditional particle swarm optimization is easy to fall into local optimization resulting in low convergence accuracy and difficult convergence. By introducing adaptive inertia weights to dynamically adjust the local search ability and global search ability of particles, the convergence speed of the algorithm is accelerated. In the process of particle evolution, neighborhood detection is used to strengthen the detection of local extremum location neighborhood, which makes the search radius of the algorithm larger in the initial stage of evolution, and gradually decreases with the increase of iteration times, which increases the refinement ability of the algorithm. Using Cauchy variation and reverse learning interactive strategy to mutate the optimal solution, the local optimal solution in Particle Swarm Optimization is broken, and the ability of the algorithm to escape from local space is effectively improved. In order to evaluate the feasibility and effectiveness of the proposed algorithm, simulation is carried out under the established UWOC weak signal detection system. Considering the special property of pilot signal, that is, some known data is inserted at the sending end and can be accurately extracted at the receiving end, it can be used as a reliable reference signal for parameter estimation. Therefore, this paper selects a specific number of code elements for parameter optimization. By taking the output SNR of the system as the selection index, the optimal system parameter which makes the output SNR maximum is searched and iterated continuously within the preset algorithm parameter range. The optimal system parameters are substituted into the fourth-order Runge-Kutta equation, the output response is obtained by discretization, and the weak light signal is detected. Finally, the error performance of bipolar non-return-to-zero signal with white Gaussian noise is compared under four detection schemes: non-stochastic resonance, fixed parameter stochastic resonance, adaptive stochastic resonance based on particle swarm optimization algorithm and multi-strategy fusion particle swarm optimization algorithm. The simulation results show that the bit error rate performance of the non-stochastic resonance system is worse than that of the other three detection schemes, and the bit error rate performance of the fixed parameter stochastic resonance system has limitations. Adaptive stochastic resonance can significantly improve the bit error rate performance of the system, especially above -6 dB, and the improvement effect is very obvious. Compared with the adaptive stochastic resonance based on particle swarm optimization algorithm, the proposed algorithm has faster convergence speed, more accurate optimization results and less error performance. In order to verify the effectiveness and feasibility of the proposed method, a UWOC experimental system is established. The experimental results show that when the received signal-to-noise ratio is -1.7 dB, the bit error rate of the proposed algorithm can reach 2×10-4, and its performance is better than that of NO-SR and F-SR, which once again verifies the effectiveness of the proposed algorithm.

As photoelectric conversion devices, organic photodetectors have the advantages of a wide range of material options, relatively simple preparation process, low production cost, lighter quality, flexibility, adjustable response spectral range, etc., and are widely used in high-tech fields, such as optical communications, medical detection, image sensors, and so on. In order to expand the spectral response range to the near-infrared, P3HT and PTB7-Th, which have complementary absorption spectra, were selected as the double donors, and non-fullerene IEICO-4F was used as the acceptor, and a ternary bulk heterojunction strategy of dual donors and single acceptor was adopted to prepare photomultiplication-type organic photodetectors with the basic structure of ITO/PEDOT:PSS/Active Layer/Al based on the solution method, with the active layer made of P3HT∶PTB7-Th∶IEICO-4F (100-x∶x∶1, wt/wt/wt). The effect of different mass ratios of PTB7-Th on the optoelectronic properties of the devices was investigated by keeping the content of the acceptor IEICO-4F in the active layer (1 wt%) constant, and x denotes the content of PTB7-Th in the donor, which was 0, 20 wt%, 40 wt% and 50 wt%, respectively. The exciton dissociation efficiency can be improved by adopting the ternary bulk heterojunction structure, in which a large proportion of donors (P3HT and PTB7-Th) surrounds a small proportion of non-fullerene acceptors (IEICO-4F), and the lowest unoccupied molecular orbitals (LUMO) energy levels of IEICO-4F differ from those of P3HT and PTB7-Th by 0.99 and 0.53 eV, respectively, and the small proportion of IEICO-4F can be used as an electron trap to assist in inducing the bending of the energy band at the cathode (Al)/active layer interface thereby realizing the tunnelling injection of holes into the external circuit and hence photomultiplication. The absorption coefficients in the spectral range of 650~850 nm increase with the increasing mass ratio of PTB7-Th, which is attributed to the good light absorption of PTB7-Th in this region. Since the HOMO of Al to PTB7-Th has a larger hole injection barrier, the hole injection barrier increases with the increasing mass ratio of PTB7-Th in the double donor, and the dark current density then decreases gradually. When the mass ratio of P3HT∶PTB7-Th∶IEICO-4F is 50∶50∶1, the dark current density is the smallest, and it is as low as 1.51×10-4 A/cm2 at -15 V. The dark current density of P3HT∶PTB7-Th∶IEICO-4F is the lowest. Upon illumination, a large number of photogenerated electron-hole pairs (excitons) move to the P3HT/IEICO-4F, PTB7-Th/IEICO-4F and P3HT/PTB7-Th interfaces and dissociate, and the electron traps in the vicinity of the cathode trap more electrons, which build up at the active layer/Al interface, thus bending the interfacial energy bands, which in turn induces the injection of hole tunneling from the external circuitry into the active layer. As a result, the photocurrent density increases significantly under reverse bias voltage, and the photocurrent density of the device at -15 V is two to three orders of magnitude larger than the dark current density. The photocurrent density and external quantum efficiency of the device under -15 V bias voltage with the same wavelength illumination firstly increase and then decrease with the increase of PTB7-Th mass ratio. Compared with the binary system P3HT∶IEICO-4F, which has only one exciton dissociation interface (P3HT/IEICO-4F), the ternary system P3HT∶PTB7-Th∶IEICO-4F has three exciton dissociation interfaces (P3HT/IEICO-4F, PTB7-Th/IEICO-4F and P3HT/PTB7-Th). Therefore, when the mass ratio of PTB7-Th is increased from 0 to 40%, the exciton dissociation efficiency of the active layer is continuously enhanced, and the optical current density and external quantum efficiency of the device are increased. The ternary system P3HT∶PTB7-Th∶IEICO-4F has three types of electronic traps (deep trap P3HT/IEICO-4F/P3HT, medium trap P3HT/IEICO-4F/PTB7-Th, and shallow trap PTB7-Th/IEICO-4F/PTB7-Th), while the binary system P3HT:IEICO-4F has only one electron trap (P3HT/IEICO-4F/P3HT). When the PTB7-Th mass ratio exceeds 40% to 50%, the number of medium traps and shallow traps in the active layer increases, along with the increasing hole injection barrier, leading to the decrease of the photocurrent density and external quantum efficiency. The mass ratio of PTB7-Th in the active layer of the best mass ratio device is 40%, and the external quantum efficiencies of the best mass ratio device under -15 V biasvoltage at 450, 520, 655 and 850 nm illumination are 2 666.40%, 1 752.11%, 1 894.26%, and 938.22%, respectively, and the responsivity is 965.80, 733.35, 998.68, and 641.91 A/W, and the specific detectivities are all over 1013 Jones. Under 850 nm illumination, the device's responsivity and specific detectivity are 2.23 and 7.08 times higher than those of the two-component device, P3HT∶IEICO-4F (100∶1, wt/wt), at the same conditions, respectively. The linear dynamic range of the best mass ratio device is 69.81 dB under -15 V bias voltage and 520 nm laser source. The results show that doping the binary system P3HT:IEICO-4F with an appropriate amount of PTB7-Th not only extends the spectral response range to the near-infrared, but also modifies the exciton dissociation interface, the type of electron traps, hole injection barrier height, and optimizing the electrical performance of the device.

To overcome the limitations of single modal object detection, this study proposes a dual modal feature fusion object detection algorithm based on CNN-Transformer. By fully leveraging the clear contour information from infrared images and the rich detail information from visible light images, integrating the complementary information of both infrared and visible light modalities significantly enhances object detection performance and extends its applicability to more complex real-world scenarios. The innovation of the proposed algorithm lies in the construction of a dual-stream feature extraction network, which can simultaneously process information from infrared and visible light images. Since infrared images have clear contour information that can be used to guide object localization, we adopt a CNN-based Feature Extraction (CFE) module to process infrared images to better capture the location information of the object in the infrared images and improve the expressive power of the feature information. On the other hand, visible light images usually contain rich detail information such as color and texture, which are distributed in the whole image, so we adopt Transformer-based Feature Extraction (TFE) to process visible light images to better capture the global context information and detail information of visible light images. This differentiated feature extraction strategy helps to fully utilize the advantages of both infrared and visible light modal images, enabling the algorithm to better adapt to object detection tasks in different scenes and conditions. In addition, we introduce a dual-modal feature fusion module, which successfully fuses feature information from both modalities through effective inter-modal information interaction. The design of this module not only preserves the features of the original two modalities, but also realizes the inter-modal feature complementarity, which enhances the expression ability of the object features and further improves the performance of multimodal object detection. To validate the effectiveness of the algorithm, we conducted extensive experimental evaluations on three different datasets, including the publicly available datasets KAIST, FLIR, and the GIR dataset that we created in-house. These datasets contain multimodal image pairs, i.e., infrared images, visible light images, and infrared-visible light image pairs. We trained and tested these multimodal images to evaluate the applicability and performance of the algorithm in various situations. The experimental results indicate that the detection accuracy of the proposed algorithm for dual modal images on the KAIST dataset is 5.7% and 17.4% higher than that of the baseline algorithm for infrared and visible light images respectively. Similarly, on the FLIR dataset, the detection accuracy for infrared and visible light images increased by 11.6% and 17.1%, respectively, when compared to the baseline algorithm. On our self-constructed GIR dataset, the proposed algorithm also demonstrates a notable enhancement in detection accuracy. Additionally, the algorithm has the capability to independently process either infrared or visible light images, with a significant improvement in detection accuracy compared to the baseline algorithm for both modalities. This further validates the applicability and robustness of the proposed algorithm. Moreover, the proposed algorithm also supports the flexibility of displaying the detection results of visible or infrared images during the visualization process to meet different needs.

Satellites and spacecrafts should possess functions as alarm and avoid through observation in the future. Hence, spatial perception is carried on spatial objectives, such as satellites, space debris and asteroids, etc. Aiming to capture and identify both point and area target, perception sensor is provided with double properties of star sensor and optical camera. In the past design examples, Modulation Transfer Function (MTF) of optical cameras reached greater than 0.45 at 70 lp/mm. The resolution ratio could meet the needs of conventional space applications. However, the sensitivity of cameras detecting fixed stars will be limited, as a result of selecting effective aperture on the basis of diffraction limit of resolution ratio. Star sensors detect high magnitude stars through relatively large apertures, on the other hand, the field of view is smaller than that of cameras'. Usually, diffused light spots are taken as evaluation function of optical systems of star sensors, and the MTF design is demanding moderately. In the light of technical weaknesses of the above mentioned two optical systems in the application of engineering, this paper designs an optical system which is applicable to wide-area spacial perception sensors, based on target equivalent magnitude model and optical imaging link mechanism, and combined with photoelectric sensing devices.In order to solve the technical problems in the process of engineering, the paper conducts an overall indicator demonstration from the perspective of optical system, based on the application background, and subsequently carries out optical path design and image quality evaluation. The optical system is designed as with full field design value of 60°, the theoretical F value of 3.0, distortion of -0.55%, magnification color aberration of less than 2 μm, and energy concentration of 100% within 15 μm. To maintain consistent sensitivity of the detector center and edge to fixed stars, the optical system uses quasi- image telecentric design scheme, with the incident angel of principle ray of 8°. In the meantime, negative vignetting design scheme is applied to improve the illumination of edge images, and the illumination of the edge is 73% of that of the center eventually. The MTF of point target of the optical system is greater than 0.75 at 50 lp/mm(the following MTFs are based on this value as a reference ). The MTF of area target is greater than 0.6 at 30 meters, and greater than 0.4 at 15 meters. In order to make the optical system engineering oriented, reduce installation costs, and optimize the optical path with low sensitivity, design steps are as follows. The first step is to use desensitization design method of “θ-Segmentation”, optimizing the incidence angle of edge field of view each mirror in the optical path, and constructing a low sensitivity error control function with the sum of squared incident angles as the core. The second step is to introduce refractive angle control to search for a wider optimization space in the process of desensitization iteration optimization. The third step is to conduct tolerance analysis and iteration of beam entry/refraction angle. Specifically, based on the results of tolerance analysis, focus on optimizing the mirror in/out angle that has the greatest impact on optical image quality degradation. At the same time, release the mirror in/out angle that has the least impact on optical image quality degradation. The optimized optical path has a maximum incident angle of no more than 32° and a maximum refractive angle of no more than 30°. The last step is proposing to compensate for the MTF of point and area targets through defocus, so that the transfer function is not less than 0.4 at 50 lp/mm.In order to verify the theoretical analysis, the performance of the lens is tested in the article, and sensitivity and accuracy are tested through field observation experiments. The lens performance test results show that the MTF of the optical system is greater than 0.5 under the above assembly tolerance conditions; The illumination of the edge field of view is 72% of that of the center field of view; The maximum distortion is -0.58%; The maximum incident angle at the edge is 8.25°; The energy concentration within the 13.5 μm diameter of the diffuse is not less than 90%; The absolute value of the chromatic aberration between 500 nm and 800 nm wavelengths does not exceed 1.53 μm in the full field of view range. The outfield stargazing shows that the maximum sensitivity of the optical system is 6.4 Mv; The average angle measurement accuracy is 0.7″, with 3σ confidence interval of 2″~3″. This article provides some reference for other optoelectronic sensors regarding the analysis methods of optical system indicators, optical system design methods, and testing verification methods.

With the continuous progress of optoelectronic tracking technology, optoelectronic tracking systems, as core components in engineering fields such as laser communication, laser guidance, and space observation, are increasingly widely used in optoelectronic platforms. However, in some special cases, the application of traditional optoelectronic tracking equipment is greatly limited due to factors such as narrow installation space, limited platform load, and higher requirements for tracking accuracy and response speed. The dual grating optoelectronic tracking device is a new type of beam deflection device that rotates two coaxial gratings for beam deflection. This device has the advantages of small rotational inertia, small volume, and high tracking accuracy, and has broad application prospects in fields such as laser communication, laser guidance, and LiDAR. In order to overcome the shortcomings of traditional airborne optoelectronic tracking devices such as large volume and weight, and achieve lightweight of the new airborne optoelectronic tracking platform. A miniaturization and high-precision design has been proposed for an optoelectronic tracking method based on a dual grating beam deflection mechanism applied to airborne platforms.This article establishes a dual grating optoelectronic tracking and aiming platform control system based on Linear Quadratic Regulator (LQR) optimal control, selects two independent rotating liquid crystal polarization gratings placed in parallel along the same axis as the beam deflection actuator , and establishes a beam deflection reverse formula based on line of sight decoupling for target tracking. The three meter collimator is used to simulate the long-distance target , the double grating photoelectric tracking and aiming system is placed on the six degrees of freedom swing table, and the azimuth axis and elevation axis disturbances are applied. The 1 053 nm laser is emitted into the double grating photoelectric tracking and aiming system through the ten meter collimator, and the tracking accuracy is tested.The dual grating optoelectronic tracking and aiming system has successfully completed tracking experiments based on platform disturbances of different frequencies and amplitudes. Through experimental data analysis, it is found that the tracking accuracy of the airborne optoelectronic tracking and aiming system based on the dual grating meets the system design indicators, with a tracking residual RMS (Root mean square) statistical value less than 350 μrad. Compared with the PID tracking algorithm, the peak to peak values of real-time miss distance data for azimuth and elevation have decreased by more than 25%. After adding LQR and Axis of Sight Decoupling Algorithm, the RMS statistical values of the biaxial miss distance under 2°@0.5 Hz and 5°@0.2 Hz disturbances are 328 μrad and 289 μrad, respectively, ensuring the reliability of subsequent experiments based on the dual grating optoelectronic tracking systemA dual grating optoelectronic tracking and aiming system based on LQR optimal control and line of sight decoupling has been designed, which has advantages such as high tracking accuracy, small moment of inertia, small weight, and small volume. The effective aperture of the liquid crystal polarization grating in the system is 50 mm, and the RMSstatistics of the off axis reflection system wave aberration are less than λ/12. Select the incident light band as λ=1 053 mm,after coating the optical antenna with a thickness of 1 053 mm, the reflectivity of the 1 053 nm laser beam is greater than 99.95%. The maximum beam diffraction deflection angle of the dual grating system is ±15°. After experimental testing, it was found that the dual grating optoelectronic tracking and aiming system has achieved tracking of simulated long-distance targets, and the system's azimuth and elevation tracking accuracy has been greatly improved, achieving the design target of a biaxial miss distance RMS less than 350 urad. The correctness and effectiveness of the combination of LQR control theory and line of sight decoupling algorithm have been verified, providing experimental reference and theoretical support for the development of new optoelectronic tracking technology based on dual gratings.

The low noise yellow-green laser at 556 nm has a wide range of applications in industries such as industrial, atmospheric remote sensing, communications, information storage, as well as in fields like food and drug detection. However, it is necessary to suppress the two spectral lines at 1 116 nm and 1 123 nm, which are close in wavelength and have similar stimulated emission cross-sections to each other, in order to ensure the oscillation of the fundamental frequency light at 1 112 nm in the cavity and achieve low noise frequency-doubled yellow-green laser at 556 nm. The conventional adoption of the F-P standard leads to considerable insertion loss, which markedly raises the oscillation threshold of the fundamental frequency light at 1 112 nm. As a consequence, the frequency-doubling efficiency and output power of the yellow-green laser at 556 nm are compromised, and there is a risk of the 1 112 nm fundamental frequency light failing to oscillate. When using a Birefringent Crystal (BC), precise adjustments of the Brewster angle of the BC, the angle between the BC surface and the optical axis of the cavity, and the phase-matching angle of the frequency-doubling crystal, are all typically required simultaneously. This intricate multidimensional angle tuning often presents formidable challenges in achieving a low noise yellow-green laser at 556 nm.In recent years, titanium carbide Ti3C2Tx has garnered significant attention in passive Q-modulated laser research due to its controllable energy band structure, wide range of nonlinear optical response, large nonlinear absorption coefficient, and high damage threshold. However, the current literature on Ti3C2Tx as a Saturable Absorber (SA) mainly revolves around 1.06 μm, 1.3 μm, 2.73 μm, and 3 μm laser wavelengths. To date, there has been no report on utilizing Ti3C2Tx for passively Q-switching of a yellow-green laser at 556 nm.The low noise passively Q-switched yellow-green laser at 556 nm is achieved through a technical approach that incorporates an 808 nm Laser Diode (LD) end-pumped Nd:YAG ceramic, a Ti3C2Tx- PVA film passively Q-switching, collaborative frequency selection and filtering with a Brewster Polarizer (BP) and a BC, as well as intra-cavity frequency doubling with a critical phase-matched type-I LBO crystal. The synergistic use of BP and BC not only ensures that only the p-polarised light at 1 112 nm achieves oscillation and amplification in the cavity, but also reduces the number of longitudinal modes at 1 112 nm, which results in the filtering of the fundamental frequency light at 1 112 nm and noise reduction of the frequency-doubled yellow-green laser at 556 nm. Using a liquid phase stripping and a spin coating methods, the Ti3C2Tx-PVA film containing 3~4 layers of Ti3C2Tx nanosheets with saturated light intensity and modulation depth near 1 μm wavelength of 2.12 MW/cm2 and 6.35%, respectively, was experimentally prepared. A passively Q-switched yellow green laser at 556 nm with Ti3C2Tx PVA thin film as SA was obtained. At 5.11 W LD pump power, the maximum average power, maximum repetition frequency, and narrowest pulse width of the yellow green laser at 556 nm were 86.2 mW, 745.8 kHz, and 46 ns, respectively, with the power instability and the laser noise only at ±0.39% and 0.37% in 4 h, respectively. Meanwhile, the beam quality factors were M2x= 1.837, M2y = 1.975.The results of power instability and laser noise of ±0.39% and 0.37% in 4 h show that the synergistic utilization of BP induces BC to exhibit greater reflective losses for the 1 116 nm and 1 123 nm spectral lines, thereby further enhancing the cavity's suppression capability towards these two lines. Considering the adopted thermal management measures, an average power of 86.2 mW, a repetition frequency of 745.8 kHz and a pulse width 46 ns also demonstrates the excellent operational reliability of the Ti3C2Tx-PVA film as SA from another perspective. In summary, the combined use of BP and BC not only ensures that only the 1 112 nm laser oscillates in the cavity, but also reduces the number of longitudinal modes in the 1 112 nm laser, thereby achieving filtering and noise reduction in the frequency doubling yellow green laser at 556 nm.“Ti3C2Tx-PVA film passively Q-switching combined with synergistic frequency selection and filtering using BP+BC” is an effective method for obtaining high stability and low noise yellow-green pulsed lasers. This method can provide high quality yellow-green pulsed laser sources for fields such as biomedical, laser measurement, pollution monitoring and spectral analysis.

Laser 3D projection technology is a key technique for achieving fast and accurate positioning of components and enabling digitalized precise assembly. This technology has greatly improved the accuracy and efficiency of production assembly. The prediction accuracy of the mirror deflection voltage in a laser 3D projection system directly affects the projection precision. The prediction accuracy of the mirror deflection voltage in a laser 3D projection system is mainly influenced by the internal parameters of the dual-axis mirror system, including the mirror deflection angle and the perpendicular length of the axis of rotation, denoted as e. In order to reduce the comprehensive nonlinear errors caused by the deviation angle deviation of the laser 3D projection system's galvanometer and the errors in the calibration of the rotation axis's perpendicular line based on the galvanometer deviation angle, and achieve high-precision auxiliary assembly for the laser 3D projection system, this paper presents a laser 3D projection galvanometer deflection voltage prediction model based on the Poisson Remora Optimization Algorithm-Back Propagation (PROA-BP). The model predicts the numerical value of the galvanometer deflection voltage using the unit vector of the laser emission direction as input. By combining the Poisson Remora Optimization Algorithm (PROA) with the Back Propagation (BP) neural network, the PROA-BP model addresses the problem of BP neural networks often getting trapped in local optima. It utilizes the BP neural network to couple and compensate for the nonlinear errors of the laser 3D projection system, thereby improving the accuracy of the galvanometer deflection voltage prediction. Through debugging and comparison, the PROA-BP neural network parameters are determined. The PROA initialization population size is 87, and the BP neural network has one hidden layer with 12 neurons. Training comparisons are conducted between the PROA-BP neural network, PSO-BP neural network, and BP neural network. The Mean Square Error (MSE) and Mean Absolute Error (MAE) of the PROA-BP model are 41.2% and 62.4% of the PSO-BP neural network, and 22.2% and 50.7% of the BP neural network, respectively. This demonstrates that the proposed algorithm yields smaller errors in the prediction of the galvanometer deflection voltage compared to the PSO-BP and BP neural networks, resulting in higher projection positioning accuracy and better fit for the nonlinear errors. Regarding the traditional model for laser 3D projection, and the PROA-BP model for predicting the galvanometer deflection voltage, projection simulations are performed. The Euclidean distance between the theoretical projection points and the actual projection points in the simulation is defined as the projection positioning error. The maximum projection positioning error of the traditional laser 3D projection model is approximately 0.5 mm, while the maximum projection positioning error of the PROA-BP model is approximately 0.35 mm. An experimental verification platform is set up to conduct projection experiments using the PROA-BP model for predicting the galvanometer deflection voltage. The experimental results show that the model achieves a projection positioning accuracy of approximately 0.35 mm, which is approximately 30% higher than the accuracy of the traditional laser 3D projection model. The model effectively couples and compensates for the comprehensive nonlinear errors caused by the deviation angle deviation of the galvanometer and the errors in the calibration of the rotation axis's perpendicular line based on the galvanometer deviation angle. It enables higher-precision auxiliary assembly and is suitable for most laser projection positioning scenarios, providing a new approach for constructing laser 3D projection models.

Laser Induced Periodic Surface Structures (LIPSSs) are a universal phenomenon produced on almost all types of materials when irradiated by linearly polarized femtosecond laser pulses with the energy fluence near the damage threshold. The LIPSSs featuring period in (deep) subwavelength scale and orientation of laser-wavelength dependence can be easily manufactured in a maskless and single-step process, providing a simple and flexible surface nano-structuring technology on diverse materials. However, the irregularity and lack of diversity of the one-dimensional (1D) LIPSSs morphology produced by a single beam of femtosecond laser degrade the application performance and scope of the surface functionalizations. Recently, the temporally delayed femtosecond lasers irradiation was reported to not only improve significantly the regularity of the 1D LIPSSs formed on metals and semiconductors but also manufacture diverse types of two-dimensional (2D) LIPSSs, including the arrays of nanosquares, nanodots, nanotriangles and nanoholes, but the profile transition among them have been less explored.In this paper, cylindrical focusing of double 400 nm femtosecond lasers with orthogonal polarizations and a time delay of 1.5 ps is utilized to controllable manufacturing of diverse types of 2D LIPSSs on molybdenum, whose morphology features were characterized by both the microscopic observation and Fourier frequency analysis. This investigation focuses on the morphology evolution among the diverse 2D-LIPSSs with the total laser fluence and the fluence ratio of the double lasers. In the experiments, the scanning velocity of the double lasers on Mo surface was fixed as v=0.01 mm/s. At the total fluence of 0.164 mJ/cm2, the double lasers with identical energies bring forth 2D square arrays structures, but with different unit profiles including nanosquares, nanocircles (ellipses) and nanostrips. The 2D square arrays structure is composed of two groups of 1D periodic grooves with orientations perpendicular to the double laser polarizations and periods of approximately 280 nm and 300 nm, respectively. With increasing the fluence ratio to 1.42∶1, the available 2D-LIPSSs on local regions transform into the hexagonal arrays of nanotriangles composed of three groups of periodic grooves with periods of approximately 270 nm, 290 nm and 320 nm, respectively. The orientation of one group of grooves is perpendicular to the polarization of the high-fluenced laser while the two other groups are neither perpendicular nor parallel to the double laser polarizations. When continuously to increase the fluence ratio, the two groups of periodic grooves with orientations non-dependence of the double laser polarizations gradually become shallower in depth. When the fluence ratio exceeds 2.37∶1, they disappear entirely, so that the double laser induced surface structure turns to 1D nanograting profile, featuring the extremely long-range uniform distribution. With optimizing the laser parameters, the large-area of 2D arrays of nanocircles and nanotriangles with high uniformity and quality are achieved.The ablation depth evolution of periodic grooves among the diverse LIPSSs implies they are originated from the periodically selective removals of material in different spatial directions induced by the orthogonally polarized double lasers. The selective removals of material are a result of the SPPs excitation and interference with the incident lasers. We utilize Finite Difference Time Domain method to numerically simulate collinear and noncollienar excitation of SPPs on the surface of one group of periodic grooves under the double orthogonally polarized lasers irradiation. Through theory analysis, the origins of 2D arrays of nanocircles and nanotriangles are attributed to two and three noncollinear SPPs excitation during the transiently correlated surface dynamics of dual laser-material interaction, respectively. The time delay between the double lasers is the crucial parameter influencing the structure uniformity in the spatial arrangement. The structural unit profile difference for the same 2D array structures are attributed to the heterogeneous laser energy depositions on different local regions. This investigation demonstrates the dual correlated femtosecond lasers irradiation provides a robust and versatile way for efficient scale-up manufacturing 2D-LIPSSs on metals, promising potential applications in the fields of optics, optoelectronic, tribology, thermology, biomedicine, etc.

Building upon the groundbreaking discovery and colleagues regarding the unique signaling role of nitric oxide (NO) in the cardiovascular system—a finding that earned them the Nobel Prize in Medicine—the therapeutic utility of gasotransmitter molecules, particularly carbon monoxide (CO) and hydrogen sulfide (H2S), has garnered considerable interest within the scientific community. While historically CO has been recognized for its toxicity, due to its ability to bind with hemoglobin forming carboxyhemoglobin (COHb) and thereby obstruct oxygen transport to tissues and organs, leading potentially to hypoxia or fatal consequences, recent studies have illuminated its critical role as a signaling molecule. This research has highlighted CO's capacity to modulate cellular behaviors and offer therapeutic advantages when administered in precise, controlled concentrations. Notably, CO has demonstrated efficacy in promoting vasodilation, reducing inflammation, combating cancer, and inhibiting apoptosis. However, the clinical application of CO as a therapeutic agent faces significant hurdles due to its brief physiological half-life, restricted transportability, and the challenges associated with maintaining therapeutic concentrations within the physiological range. Recent advancements have led to the development of carbon monoxide-releasing molecules (CORMs), which provide a controlled and efficient delivery of CO, surpassing the stability issues of direct inhalation and minimizing biosafety risks. The versatility of CORMs supports targeted delivery via chemical modifications and encapsulation in drug carriers, enabling diverse therapeutic uses. Traditional CORMs, often metal carbonyl compounds, consist of a central metal ion bonded to ligands, typically organic molecules, facilitating CO release through coordinated mechanisms. Notably, iron pentacarbonyl (Fe(CO)5) exemplifies such CORMs, releasing CO via ligand exchange. This innovation in CORM design, including the adjustment of ligands and coordination strategies, signifies a pivotal advancement in exploiting CO's therapeutic benefits.To achieve more precise control over the release concentration of carbon monoxide (CO) at pathological sites and to address the challenges associated with poor spatial accuracy of delivery and unclear release mechanisms, researchers have turned their attention to designing carbon monoxide-releasing molecules (CORMs) sensitive to stimuli such as light, sound, magnetism, and heat. This innovative approach not only deepens our understanding of CORMs from a multidimensional perspective but also expands their potential applications. Consequently, an increasing focus has been placed on the development of photo-responsive carbon monoxide donor molecules (Photo-CORMs). Photo-CORMs, which release CO under specific wavelengths of laser light, leverage the advantages of efficiency, safety, and controllability. This light-responsive CO release mechanism endows Photo-CORMs with substantial potential for applications in biomedicine and beyond. Current research on Photo-CORMs predominantly revolves around metal carbonyl complexes. Despite the many benefits of traditional metal carbonyl Photo-CORMs, their major limitation lies in the rapid exchange of ligands under physiological conditions, leading to premature CO release and, consequently, suboptimal therapeutic outcomes. Moreover, traditional metal-centered Photo-CORMs present challenges such as high costs, poor stability, selective deficiency, and intrinsic toxicity.Addressing the drawbacks of traditional metal-centered Photo-CORMs, the scientific community is increasingly exploring organic Photo-CORMs, such as cyclic aromatic α-diketones, fluorescein analogs, flavonols, and 3-hydroxybenzo-[g]quinolones. These organic variants offer enhanced biocompatibility and can be activated across a broad light spectrum, from ultraviolet to near-infrared, for CO release. Their adaptable structural design permits modifications to tailor properties and reactivity, enabling the precise engineering of CO release mechanisms for targeted biomedical applications. Previous reviews have summarized traditional CORMs and Photo-CORMs. As a supplement to these reviews, this paper focuses on recent research on organic Photo-CORMs, providing a concise introduction to their classification, photophysical properties, and discusses their modes of administration and roles in disease treatment. Ultimately, this review offers insights into the future development of organic Photo-CORMs, guiding the design and development of more effective therapeutic strategies. This endeavor not only underscores the importance of continued innovation in the field of gasotransmitter research but also highlights the potential of organic Photo-CORMs to revolutionize therapeutic approaches through precise, controlled release of CO.

Dynamic Light Scattering (DLS) technology is an effective method to measure Particle Size Distribution (PSD), and this technology is widely used in chemistry, medical treatment, materials and other fields. DLS technology obtains the Autocorrelation Function (ACF) of the scattered light intensity signal by the autocorrelation operation of scattered light, and obtains the PSD by inverting the ACF of the light intensity. Inverting the ACF needs to solve the first kind of Fredholm integral equation which belongs to ill-conditioned problem, and this kind of equation can be solved by Tikhonov regularization. Tikhonov regularization controls the accuracy and stability of the solution by adjusting the regularization parameter, which is usually selected by L-curve criterion. L-curve criterion introduces the stability analysis through the vector modulus of the solution, but it can not get ideal inversion results under the condition of wide particle size distribution. Morozov's Discrepancy Principle (MDP), another method to select regularization parameter, can select parameter according to the noise level of electric field ACF. But the raw data noise level is usually unknown, which causes it difficult to apply MDP in actual measurement.Compared with the inversion of narrow particle size distribution, the inversion of wide particle size distribution needs more accurate regularization parameters to ensure the accuracy of the inversion results. To improve the accuracy in the widely distributed particle system, we got the noise component of the electric field ACF through wavelet packet decomposition, and measured the amplitude of the noise component to estimate the noise level. The noise level was brought into MDP to establish the fitness function, the initial population was generated within the empirical range of the regular parameters, and then the fitness function and the initial population were brought into the Genetic Algorithm(GA) to find the regular parameters. The method proposed above is named as MDP-GA. Thus, the problem of MDP in actual measurement is solved. Compare the MDP-GA method with the L-curve criterion under simulated and measured conditions. In comparison, different distributions under different noise levels are selected, and take peak error, distribution error and repeatability error as performance indicators. The inversion results show that there is no significant difference between MDP-GA and L-curve criterion under the condition of narrow particle distribution, at the same time, the inversion results of MDP-GA method are better than those of L-curve criterion under the condition of wide distribution. Under the condition of wide particle size distribution, the false peak and peak offset that may occured in L-curve criterion are avoided by the MDP-GA method.

In order to achieve the detection of methane gas concentration and monitoring of methane leakage, and to improve the monitoring efficiency and accuracy, a high sensitivity near-infrared methane gas detection technique based on the Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology is proposed.As an absorption spectroscopy technology, TDLAS is based on the Lambert-Beer law. When the emission laser makes contact with gas molecules, the gas molecules will absorb the laser energy if the wavelength of the laser coincides with the absorption line of the gas molecule. And it is known that the absorption rate of gas is directly proportional to the effective absorption distance. A larger attenuation of laser intensity tends to produce a stronger TDLAS sensor signal. Therefore, it is necessary to increase the amount of light intensity attenuation by using a long optical path gas cell. At the same time, in order to improve the measurement sensitivity and detection limit of the system, the system uses a self-developed gas absorption cell. Simulation design of Herriott-type gas absorption cell uses TracePro optical simulation software. Under the consideration of no excessive interference, uniform spot distribution, and reasonable angle between incident and outgoing rays, two concave spherical mirrors with a diameter of 50.8 mm are designed to form a Herriott absorption cell with a cavity length of 220 mm.The system adjusts the current injected into the Distributed Feedback (DFB) laser to make its output central wavelength at 1 653.7 nm and serve as the detection light source of CH4. The thermo electric cooler temperature control circuit adjustes the temperature stability of the laser and is used to operate the laser at 26 ℃. The lock-in amplifier generates low frequency sawtooth wave signal and high frequency sine wave signal. The two signals are superimposed by the adder. The emitted laser light is absorbed by the measured gas and emitted from the end of the gas chamber to the photodetector. The photodetector converts the optical signal into a corresponding electrical signal. After being collected, the signal is sent back to the lock-in amplifier for data processing. The results are displayed on the oscilloscope.By configuring different concentrations of CH4 gas, the correctness of absorption spectrum selection and the feasibility of system construction are verified by the direct absorption method. The different low concentrations of CH4 gas are studied experimentally, and the second harmonic signal is recorded and linearly fitted. The peak value of the second harmonic signal shows a good linear relationship with concentration, and the linearity is 0.998 52. The concentration of the gas to be measured can be calculated by fitting the linear equation. The experiments have demonstrated that the dependability of the second harmonic signal for concentration detection and, to a certain extent, confirm the stability of the detection system. The lower detection limits of the system can reach 4.82 ppm for methane. Allan variance analysis is conducted within 960 s with CH4 of 390 ppm. As the integration time increases, Allan variance shows a tendency to decrease and then stabilize. When the integration time reaches 112 s, Allan variance is in a stable state, and the sensitivity of the detection system is 4.27×10-7, which realizes the high-precision measurement of CH4 gas.Test findings demonstrate that the precision, accuracy, and detection limits of the system have been improved based on the use of a low-cost light source and a small-sized absorption cell. The proposed system combined with the method can be widely used in gas monitoring and early warning of mine disasters, gas leakage monitoring, and early warning of hazardous chemical field stations and transportation pipeline networks.

In order to further improve the detection sensitivity of multi-component trace gases, an acoustic resonant cavity and an interferometric fiber optic acoustic wave sensor were used to enhance the excitation and detection of the Photoacoustic (PA) signal. A fiber optic PA sensing system was designed to achieve high-sensitivity detection of C2H2 and CH4 gases. To increase the amplitude of the PA response and reduce the cross-interference of other gases, two DFB lasers with center wavelengths of 1 532.83 nm and 1 650.96 nm were selected as the excitation light sources for C2H2 and CH4. Through the digital-to-analog converter, the working parameters such as modulation frequency, bias current and modulation depth of the two DFB lasers were controlled by FPGA. Two near-infrared lasers with different wavelengths were coupled through a wavelength division multiplexer and then incident into the PA cell, achieving dual-component gas excitation of C2H2 and CH4. To further improve the detection limit of gases, a multi-pass device composed of two coaxial concave mirrors combined with a resonant PA cell formed a multi-pass resonant PA cell. The excitation light was reflected multiple times in the multi-pass resonant PA cell, which increased the interaction length between the target gas and light, increasing the effective power of the excitation light. The Micro-electro-mechanical Systems (MEMS) cantilever in the fiber optic acoustic sensor was used as the acoustic sensitive element, and a fiber optic Fabry-Perot (F-P) interference structure was designed to convert the deflection displacement of the cantilever into the change of the F-P cavity length. A superluminescent diode with a central wavelength of 1 550 nm was used as the detection light source. The emitted broadband light entered the acoustic wave sensor after passing through the optical fiber circulator. The F-P interference spectrum containing PA information was detected by the miniature optical fiber spectrum module. The signal processing circuit performed high-speed acquisition and real-time processing of the F-P interference spectrum. By using high-resolution spectral demodulation technology, ultra-high sensitivity PA signal detection based on fiber optic F-P sensor was realized. In order to obtain the highest detection sensitivity, the relationship between the PA response and the modulation parameter was measured by adjusting the modulation current of two DFB lasers. The PA response was measured under different currents, and the system obtained the best detection performance when the modulation currents of the C2H2 laser and the CH4 laser were set to 8.5 mA and 4 mA, respectively. The frequency response of the system was tested to obtain the best PA signal amplitude. In the range of 500 Hz to 1 250 Hz, the modulation frequencies of the two DFB lasers were adjusted, and the resonance peak appeared at 1 660 Hz in the two frequency response curves. The linearity of the sensing system was evaluated. The gas mixtures of C2H2/N2 and CH4/N2 with different concentrations were flushed into the PA cell, and the PA response of the system to C2H2 and CH4 was analyzed. In the concentration range of 0 ppm to 100 ppm, there was a good linear relationship between the excitation PA signal amplitude and the concentration of the two mixed gases, and the linear responsivity of the system to C2H2/N2 and CH4/N2 were 7.39 pm/ppm and 5.67 pm/ppm, respectively. Pure N2 gas was pumped into the PA cell to test the noise level of the system and evaluate the stability of the sensor. Two sets of noise data were tested repeatedly, the deviation (1σ) were 0.364 pm and 0.365 pm, and the average value was 0.36 pm. Based on sensitivities of 7.39 pm/ppm and 5.67 pm/ppm for C2H2 and CH4 gases, detection limits of 48.7 ppb and 63.4 ppb were obtained, respectively. The detection sensitivity and stability of the system were evaluated by Allan-Werle deviation analysis. When white noise dominates, the Allan-Werle variance value decreased as the averaging time increased. With an average time of 400 s, the results of Allan-Werle analysis of variance showed that the detection limits of the system for C2H2 and CH4 gases reached 2 ppb and 3 ppb, respectively. The Normalized Noise Equivalent Absorption (NNEA) coefficient normalized the absorption line intensity and the effective power of the excitation light. The output powers of C2H2 and CH4 lasers were 14.7 mW and 21.9 mW respectively. Therefore, the calculated NNEA is 8×10-10 cm-1 WHz-1/2. The designed optical fiber PA sensing system realized the high sensitivity detection of C2H2 and CH4 gas.

To solve the problems of inaccurate results in the theoretical calculation of Fiber Bragg Grating (FBG) sensors for strain testing at high temperatures, and the complexity of the preparation process of special fiber gratings, moreover, to enhance the operability of strain testing in practical engineering by using FBG, this paper proposes a bare FBG sensors testing method based on the clamp-adhesive type, and combines the temperature compensation method, to achieve the accurate measurement of 3 000 με within 250 ℃.Firstly, for the problem of temperature-strain cross-sensitivity, the temperature compensation method is proposed to remove the effect of temperature, and the formula is derived. Based on this formula, the temperature compensation based FBG sensor temperature decoupling method is by using another FBG sensor that only responds to temperature. Then, after the two FBG sensors are integrated with the substrate, a suitable paste method can be selected so that one sensor can only sense temperature, and another sensor can sense temperature and strain, and the real strain value can be obtained after the temperature value brought into the formula.Secondly, the strain transfer rates of two FBG integration methods (clamp-adhesive and surface-adhesive) are compared by finite element analysis, and the simulation results indicate that the strain curve of the clamp-adhesive method fits the substrate strain curve better, and the strain transfer rate is 99.47%. In contrast, the gap between the strain of the surface pasted method and the substrate strain is larger, and the strain transfer efficiency is 95.8%. Therefore, the strain transfer efficiency of the clamp-adhesive sensor is higher than that of the surface-adhesive FBG sensor. In addition, the surface-adhesive type needs to cover the grating of the Bragg grating sensor with glue, and the change of the material properties of the adhesive layer in the high temperature environment has a large impact on the reflection of the grating, so the penetration of the glue into the fiber grating area will make the grating fail, which has a large impact on the strain measurement.Thirdly, with reference to the strain transfer theory of clamp-adhesive FBG sensor, the influence factors of the scale ratio on the strain transfer rate are analyzed. It can be concluded through simulation that when the scale ratio is greater than 1, the strain transfer rate decreases at a faster rate. When the scale ratio is less than 1, the strain transfer rate only differs by 0.1%. Considering the influence of the coverage area of the adhesive layer on the adhesive firmness and the fluidity of the adhesive, the chosen gauge scale is 1.Finally, in the experiment, the scale ratio of the clamp-adhesive FBG sensor is 0.87 due to the glue fluidity and manual operation. Meanwhile, a fiber grating temperature sensor is connected as temperature compensation. Then, the temperature/strain calibration tests are carried out, resulting in the fiber temperature sensitivity coefficient of FBG1 (12.393), the strain sensitivity coefficient (1.596) and the fiber temperature sensitivity coefficient FBG2 (12.293). The high-temperature tensile test of 3 000 με within four temperature gradients from 100 °C to 250 °C (100 °C, 150 °C, 200 °C and 250 °C) is carried out in a tensile testing machine. The results show that the strain measured by the fiber grating sensors based on the temperature compensation decoupling is similar as data from the standard high-temperature strain gauges, in which maximum relative average error of 2.26%. The results of the research present the reference significance on the engineering application of the strain measurement and integration method of FBG sensors according to a high temperature environment.

The characteristic size and surface quality of O-ring seals (hereinafter referred to as “O-ring”) used in aerospace and guided weapon systems are important factors affecting the reliability of the main engine, and must be 100% fully checked. Due to the flexible characteristics of the O-ring material and the omnidirectional curved surface feature of the outer surface, the current manual measurement and detection methods have three major drawbacks: low efficiency, unstable results and high manpower consumption, which can no longer meet the requirements of the rapid development of aerospace and defense industries. With the advent of convolutional neural networks, target detection algorithms based on deep learning are widely used in the field of target detection because of their simple structure and good versatility. The micro-aerospace the O-ring studied in this paper has an inner diameter size range of Φ1.8 mm-Φ20 mm. Through the analysis of the surface topography of the defects, it is found that most of the defects have the characteristics of tiny targets and the pixels of the marked defects are less than 0.33% of the total pixels of the image, which is a typical tiny target detection. Compared with other computer vision tasks, tiny target detection has problems like fewer available features, higher positioning accuracy requirements, lower proportions of tiny targets in datasets, sample imbalance and tiny target aggregation. Because of its omnidirectional curved surface features, the O-ring presents severe bright areas and dark areas in images from any angle. The random defects are intertwined with these non-uniform areas which causes great difficulties in the detection and classification of surface defects. Especially for micro-O-ring, tiny defects impose higher demands on algorithm sensitivity and classification ability. Although the target detection algorithm based on deep learning has good detection capability but its detection efficiency is relatively low, and there is room for improvement in detection accuracy.To address the above problems, two deep-learning-based algorithms are proposed for detecting surface defects on the O-ring. By adding multi-head attention mechanisms to the inverse residual blocks of MobileNetv2, we constructed a lightweight backbone network called Efficient Model. By using the Next Hybrid strategy, we fused multiple attention mechanism modules from the industrial-grade Transformer network to build a Next Generation Vision Transformer backbone network. In each of these two backbone networks, feature extraction networks were added to design the Efficient-FPN Model and Transformer-FPN Model detection algorithms. The experimental results show that the mAP of the Efficient-FPN Model and Transformer-FPN Model detection algorithms is higher than that of YOLOv5s, YOLOv5x and YOLOv5z, among which the mAP of the Transformer-FPN model is the highest, reaching 91.4%. The Efficient-FPN Model has the fastest detection speed of the five models, reaching 110.8 frame/s. The mAP of the Efficient-FPN Model reached 86.1%, which was also higher than other YOLOv5 algorithms, and it was the detection model with the best comprehensive performance. The above algorithm is deployed in the self-developed intelligent measurement and inspection equipment of aerospace seal ring, and the purpose of detecting omnidirectional curved flexible parts is realized quickly and accurately.

In order to enhance the retention of angle information in complex flow fields and reduce edge step distortion and blur effects caused by the reconstruction process, this paper proposes an optical flow pyramid interpolation optimization method for particle image velocity measurement based on the multi-scale pyramid iterative optical flow algorithm and nearest neighbor interpolation. By calculating the distance between each site and grid points, the grid point with the smallest distance is identified and its value is assigned to the site. In addition, the nearest pixels with similar gradient directions are searched in the current image plane for corner correspondence. This approach preserves original edges while reducing step distortion and blurring effects commonly encountered in optical flow algorithms. As a result, it helps minimizing reconstruction angle error and root mean square error, particularly at image edges.The proposed algorithm was tested for its reconstruction effect in different flow fields through simulation experiments, including single vortex current, double vortex current, and DNS turbulence, under various parameters. Both the proposed algorithm and common algorithms were employed to simulate these flow fields, and the reconstructed results were compared with the true values. The accuracy of the algorithm was quantitatively evaluated using root-mean-square error and average angle error. The results demonstrate that the proposed algorithm achieves closer reconstruction results to the true values across all three flow fields. Specifically, compared to pre-optimization, the root-mean-square error and average angle error were increased by 15.96% and 19.87% respectively in the single vortex current field, by 15.03% and 19.56% in the pair vortex current field, and by 14.90% and 17.37% in the DNS turbulent field. Notably, at image edges, the proposed algorithm exhibits smaller reconstruction errors which validate its correctness while also indicating its ability to effectively retain angle information thereby reducing reconstruction errors.The accuracy of PIV reconstruction is influenced by two important parameters, namely particle size and displacement. To investigate the impact of particle size and particle displacement on the reconstruction effect of PIV in the flow field, a total of 50 000 imaging particles were randomly distributed in a two-dimensional imaging plane measuring 256 px×256 px. The previous-used three flow fields, including single vortex current, double vortex current, and DNS turbulence, were subjected to 400 iterations of optical flow using both the proposed algorithm and the conventional optical flow algorithm. This analysis aimed to assess how particle size and displacement affect the Root Mean Square Error (RMSE) and Average Angular Error (AAE) of the reconstructed results. The findings demonstrate that under different conditions of particle size and displacement, the proposed algorithm outperforms the conventional optical flow algorithm in terms of fitting accuracy as well as precision during optical flow iteration. Specifically, when keeping particle size constant, small displacements can increase RMSE accuracy by approximately 18%, while large displacements can enhance it by about 15%. Moreover, when maintaining a constant displacement size within a range of 1 px ~7 px for particle sizes, both RMSE and AAE values obtained from the proposed algorithm surpass those achieved with common optical flow algorithms.To verify the performance of the algorithm in practice, an experimental system based on two-dimensional PIV principle is built. The 100 micron PSP particles were used as tracer particles, and a certain amount of tracer particles was added to the quartz container containing dimethylsilicone oil as the flow field to be measured. An electric slide table is used to rotate and inject water into the flow field to simulate the vortex current field and jet field respectively. The images of the flow field to be measured captured by the CMOS camera are put into the PIV system for analysis and reconstruction. The reconstruction results show that the optimized algorithm in this paper can obtain a velocity field consistent with the manifold of common algorithms, which verifies the correctness of the proposed algorithm. It also shows that the proposed algorithm has good practicability in the actual complex flow field.

The large-scale measurement technology is widely used in aerospace equipment assembly, precision measurement of geometric quantities, mobile robot positioning, and navigation in the field of industrial manufacturing. As the measurement objects become more complex, refined, large-scale, and multi-target, the single-station measurement mode has become difficult to complete the corresponding measurement tasks. Compared to single-station systems, distributed measurement systems can control the measurement range by adding or removing measurement units, and flexibly adjust the measurement scheme according to the measurement requirements, fully leveraging the advantages of each measurement unit. These characteristics make distributed measurement systems have higher measurement accuracy and a wider measurement range compared to single-station systems. Accurate Laser Positioning Systems (ALPS) for large-scale measurement are typical distributed measurement systems. During measurement, each measurement unit of the accurate laser positioning system obtains measurement data in its independent local coordinate system. To achieve networked measurement of multiple measurement units, it is necessary to calibrate the local coordinate systems of each measurement unit in advance. When using the method based on a standard ruler to unify the coordinate systems of measurement units, it is necessary to manually move the standard ruler to different positions in the measurement space for measurement, in order to cover the entire measurement space. The application scenarios of distributed measurement systems usually have a large measurement range, high accuracy requirements, and a complex measurement environment. In order to adapt to the measurement task, the more positions the standard instrument is moved, the higher the calibration accuracy. However, each movement of the standard ruler inevitably increases the time cost of calibration, sacrificing efficiency to obtain higher accuracy. Moreover, the coordinate system based on a standard ruler limits the flexibility of adding measurement units or mobile stations to the distributed measurement system. In response to the low efficiency of the coordinate system based on a standard instrument during the calibration process, this paper proposes a fully automatic coordinate system calibration method for large-scale measurement systems. This method uses two measurement nodes with known coordinates in the local coordinate system of each measurement unit as mark targets. The measurement units measure the mark targets of each other to obtain the coordinates of the mark points in different coordinate systems, and uses these coordinates to establish three-dimensional geometric constraints, thereby automatically calibrating the coordinate transformation relationship between different coordinate systems. In addition, when a measurement unit moves or new measurement units are added to the original measurement network, the method proposed in this paper can naturally realize the automatic networking between measurement units without the need to recalibrate the measurement field. This method greatly improves the calibration efficiency of the system compared to the traditional standard ruler method. Moreover, compared with existing automatic calibration models, the method proposed in this paper can automatically calibrate multiple measurement units in actual measurement scenarios, solving the problem of existing automatic calibration models that can only calibrate two measurement units. Additionally, the manufacturing process of the marker targets is simple, which provides a new theoretical basis for the industrialization of distributed measurement equipment with automatic calibration function. Finally, this paper verifies the proposed method using the precision laser positioning system. In a measurement space with a distance of about 2 m from the measurement unit deployment area and a size of 5 000 mm×5 000 mm×500 mm, length data of a standard ruler (1 156.704 mm) is sequentially measured at 12 different positions. The deviation of the measurement results relative to their reference length is recorded, and the experimental results show that the accuracy of length measurement is within 0.46 mm/m. In addition, this paper uses a target ball to perform a comparative test of measurement points between the precision laser positioning system and the laser tracker. The experimental results show that the standard deviation of three-dimensional coordinate measurement is within 0.026 mm after using the method proposed in this paper to calibrate the coordinate system of the accurate laser positioning system. The maximum errors in coordinate measurement in the x, y, and z directions are 0.5 mm, 0.55 mm, and 0.5 mm, respectively, which can meet the needs of the majority of industrial measurement. Furthermore, this paper's method achieves automatic calibration of local coordinate systems between measurement units, greatly reducing the manual cost during the coordinate system calibration process. Compared to traditional standard ruler calibration methods, this method improves the calibration efficiency by more than 10 times and solves the problem of the inability of existing automatic calibration models to automatically network multiple measurement units.

The aberration of the telescope system itself can easily lead to the change of its optical ellipticity, which interferes with the detection of dark matter. To ensure the accuracy of dark matter detection, the ellipticity of the telescope system must be precisely controlled. In this paper, an optical design method for telescope with freeform surfaces incorporating optical ellipticity criterion is proposed. It addresses the challenge of traditional optical design methods in which optical design software is unable to directly take the ellipticity in the merit function. Implementing the numerical interaction between optical design software Zemax and numerical calculation software Matlab through MZDDE. Extract point spread function data from Zemax, calculate the ellipticity value using Matlab algorithm, and then import it into the merit function editor of Zemax to assign weights for optimization. In this way, the astronomical ellipticity is included throughout the optical design procedure. A complete evaluation function system integrating wavefront aberration and ellipticity has been constructed. Based on the relationship between ellipticity and non-rotationally symmetric aberrations such as coma and astigmatism, we put forward the principle of preferentially correcting the aberration components which exhibit stronger correlation with ellipticity. With the help of the full-field aberration map in the optical design software, we analyze the correlation between the aberration nodal distributions and ellipticity node distributions. And the specific freeform surface items to be modified and the surfaces of the freeform items to be added in each step are determined based on the aberration theory. The aberration components with strong ellipticity correlation are taken as the priority correction parameters for iteration, which contributes the design idea of incorporating the ellipticity criterion into the main off-axis aberration correction. Based on the evolution law of aberration nodes and ellipticity nodes in the optimization process of the off-axis three-mirror system, an optimization strategy for the Zernike term of the freeform surface type is established. Accordingly, an off-axis three-mirror freeform surface astronomical telescope is designed, with an effective focal length of 600 mm, an aperture of 200 mm, and a field of view of 4°×4°. Through the joint optimization of wave aberration and ellipticity, the imaging quality and optical ellipticity are synchronously and effectively controlled. The wave aberration is close to the diffraction limit, with the maximum ellipticity value of 0.030 3, and the average value of 0.015 6. It meets the requirements of the dark matter detection with the maximum ellipticity value of less than 0.15 and the average value of less than 0.05. The traditional optimization design method adopts a gradual upgrade of surface shape, gradually adding freeform terms in order from low order to high order, and continuously maintaining the variability of system structural variables during the addition process. This method lacks optimization targeting for the current aberration of the system, and blindly using freeform terms on multiple surfaces will lead to aberration correction degradation and unnecessary freeform surface deviation. Compared with the traditional aberration correction optimization method from low-order terms to high-order terms, the application of the proposed method adopts relatively small freeform surface deviation. By adjusting the aberration nodes, the imaging quality and ellipticity performance of the designed freeform surface telescope are controlled synchronously. The maximum value of ellipticity is further compressed, and the ellipticity distribution is more evenly distributed. The design freedom of the freeform surface is fully leveraged.

The projection model regulates the mapping relationship between the object and image for the imaging system, where they are related by the focal length. The distortion is defined as the departure from the similarity between the object and image, or the departure from the targeted projection model. Thus, the focal length and distortion represent the actual relationship of the optical system. The focal length is the most important and basic parameter of an optical system, which is theoretically defined utilizing the “minor aperture method”. According to the regulation of “minor aperture method”, the ray close and parallel to the optical axis is traced, and then its angle of convergence after passing through the optical system is recorded for focal length calculation. This regulation is easy to execute during the optical design process but hard to execute for the measurement of the built performance of the optical system. The “minor image height method” is the frequently adopted regulation for focal length measurement, in which ray with minor field of view is traced, and the corresponding image height is recorded for focal length calculation. The “minor image height method” is easy to execute for both design and measurement, and aligns well with the definition of projection. Therefore, if the definition of the focal length is developed from the on axis field of view to the off-axis field of views, then the local focal length which is a field dependent parameter is involuntary generated. And the “minor image height method” is adopted for local focal length definition, in which the image height increment for a minor angle increment is regulated for each field of view. Moreover, the distortion is represented by the variable local focal length for different field of views. And then, the local focal length can be adopted in the process of optical system design for distortion control, for its calculation in the design coincides well with the measurement in the experiment, which is the outstanding priority according to its regulation. A fisheye lens with field of view of 160°, F-number of 4.2, on focal length of 1.61 mm is firstly designed utilizing the local focal lengths for 11 sampled field of views as the target. It is composed of 6 pieces of lenses, in which one aspherical surface is set at a plastic lens, and the equidistant projection is fulfilled. Inspired by the foveated fisheye, the theory of high resolution with rectilinear projection in the central field of view is proposed, and the aforementioned fisheye lens is successfully transformed to the configuration with equidistant projection for the 50% central field of views, adopting the local focal length as the optimization target. Other than objects in the infinity, there are some cases in which the objects is imaged from finite distance, and the object is sometimes even curved. The wide angle lenses with field of view of 120°, F-number of 2.8, on focal length of 1mm are then designed still utilizing the local focal length as the optimization target. The curved objects are 1 000 mm away from the lenses, with the radius of curvature of 800, 1 000, 1 200, -20 000 mm and infinity, corresponding to convex spherical objects, concave spherical object and plane object respectively. The target local focal length is derived according to the imaging purpose for equal resolution on the curved objects. Diffraction limited imaging quality is achieved, and local focal length relative error is constrained to less than 0.6% with 11 sampled field of views, and the distortion is then less than 0.21%. The generation of local focal length provide a novel parameter for optical system design with complex projections, leveraging its priority of design and measurement coincidence.

The confocal displacement sensing system employs a small-aperture dispersive objective lens, achieving an extended working distance and overcoming limitations imposed by axial dispersion size. To meet the application requirements of small hole inner diameter or internal defect detection, a small-diameter dispersive objective based on a Gradient Index (GRIN) lens is designed. Through the study and correction of optical aberrations, the performance of the spectral confocal displacement sensing system has been optimized. GRIN lenses possess multiple degrees of refractive index parameters, offering an effect equivalent to homogeneous optical elements with complex shapes, high process demands, and elevated costs. They feature simple geometrical shapes, lightweight structures, compact sizes, excellent optical performance, and are conducive to optical integration. To analyze the impact of optical aberrations of GRIN dispersive objective on peak wavelength extraction and achieve performance optimization of the spectral confocal displacement sensing system based on GRIN dispersive objective, this paper investigates the influence of optical aberrations of GRIN dispersive objective on peak wavelength extraction and establishes an optical aberration fitting algorithm. Initially, considering the optical properties of the GRIN dispersive lens, the study utilizes the wavefront aberration equation in Fourier optics. It combines the refractive index variation of the GRIN dispersive lens with different wavelengths and curvature radii. Physical models for spherical aberration, astigmatism, and coma of the GRIN dispersive lens are established and analyzed within the spectral confocal vertical sampling sequence. An optimized distribution function for the aberrations of the GRIN dispersive lens is then developed, establishing relationships between various aberrations and wavelength distributions. Subsequently, various monochromatic aberrations and combined aberrations are simulated to analyze their impact on the distribution of peak wavelengths. Three fitting algorithms are employed to extract peak wavelengths under different aberrations, revealing the wavelength shift caused by optical aberrations of the GRIN dispersive lens. Finally, Gaussian fitting, Zernike polynomial fitting, and sinc2 function fitting are applied to perform data fitting and analyze fitting errors for the axial response signals under different aberration scenarios. The results indicate that spherical aberration, astigmatism, and combined aberrations can cause axial response peak wavelength shifts. When the spherical aberration is 1, the peak wavelength shifts by 6.28 nm. For spherical aberration greater than 1, a double peak appears, and the larger the spherical aberration, the greater the peak wavelength shift. The impact of astigmatism on peak wavelength shift is smaller than that of spherical aberration. Combined aberrations have the greatest effect on peak wavelength, leading to the simultaneous elevation of sidelobes for three peaks, causing a significant spectral confocal position deviation or system error. The influence of off-axis aberration can be ignored. Finally, using three different methods to fit and analyze axial response signals under the influence of various aberrations, the results indicate that, in the case of optical aberrations in the GRIN dispersive lens axial response peak wavelength extraction, Gaussian fitting improves the accuracy of peak wavelength extraction. However, it's fitting performance for sidelobes is relatively poorer. In comparison to Gaussian and Zernike polynomial fitting, sinc2 function fitting not only provides a good fit for the main peak but also yields better fitting results for the sidelobes than Gaussian and Zernike polynomial fitting. The dispersive lens is the central component of the spectral confocal displacement sensing system. The system's measurement precision is closely related to the resolution of the dispersive lens. The accuracy of measurements and the measurement range depend on the magnitude of the axial dispersion of the dispersive lens. Optical aberrations of the dispersive lens affect the axial distribution of the focal wavelength, causing interference in the collected spectral response data, consequently impacting the system's measurement performance. The research findings are of reference significance for establishing error correction and compensation algorithms for peak wavelength extraction affected by aberrations, further enhancing the measurement performance of spectral confocal systems.

Long-wave infrared optical system with long focal length has been widely used for the fields of military, industrial, civil, medical and so on. People often pursue the large aperture imaging to obtain better imaging, which makes this kind of optical systems have the characteristics of long focal length, large aperture and wide working band range, and it results in serious aberrations and difficult to correct. In order to reduce the complexity of the structure of infrared optical system, the catadioptric structure design is often used to reduce the total length of the optical system; therefore, based on the structure of two reflection mirrors, the optical system was composed of a set of correcting refraction lens after. Firstly, applying the method of coaxial dual mirror optical structure determining parameters to solve the optical parameters of the primary and secondary lens, and an aberration correction spherical lens group consisting of four refraction lenses is added behind the optical structure, to form the initial structure of the long-wave infrared optical system design with long focal length; and then, applying the three conditions of focal degree distribution, heat aberration dissipation and achromatic dissipation to realize the athermalization design, the optical surfaces of the primary and secondary mirrors applied secondary aspherical to design, and combining with optical design software to build the aberration optimization function of the optical system to optimize the aberration. Finally, applying the design method, a long-wave infrared athermalized optical system with large aperture and long focal length is designed, and the operating band of the optical system is 8~12 μm, the focal length is 800 mm, the full field of view angle is 0.6°, the F number is 2.5, the obstruction ratio is 0.2, the total length of the optical system is 344.62 mm. In the operating temperature range of -40 ℃~60 ℃, the value of modulation transfer function in the full field of view angle is greater than 0.25 at the Nyquist frequency of 20 lp/mm. The designed long-wave infrared and athermalized optical system with large aperture and long focal length has the characteristics of compact structure and is good and stable in imaging performance, and realize the optical passive athermalization design of optical system in the case of operating temperature range of -40 ℃~60 ℃. The design method of long-wave infrared and athermalized optical system with large aperture and long focal length discussed provides a reference method for the design of such optical systems, which is of great significance and has great application value.

In order to solve the problem of slow test speed of traditional generalized elliptical mechanical rotation, it is proposed to use a circular elastomeric modulator with better symmetry to replace the electro-optical phase modulator to achieve ultra-high-speed measurement.By decomposing the internal stress standing wave of the elasto-optic crystal into two columns of traveling waves with a phase difference of π/4, it is deduced that when the driving voltage amplitudes of the two piezoelectric actuators are equal and the phase difference is π/2, the fast axis of the elastooptic modulator makes a circular motion with an angular frequency of f/2. However, during the actual experiment, the fast axis direction angle transformation of the photoelastic modulator cannot be seen. Therefore, in order to more vividly verify the pure traveling wave modulation mode, COMSOL software is used for simulation. Using the transient solver in COMSOL, simulations are performed based on the conditions derived from theory to obtain a periodic surface vibration displacement of the photoelastic modulator. The simulation results show that when the elastic optical modulator is in pure traveling wave modulation mode, it can be regarded as a phase modulator that rotates at high speed in the fast axis direction. Since the support structure of the common octagonal elastic optical modulator adopts the chamfer position with the smallest vibration displacement for support and fixation, it is different from the commonly used two-dimensional octagonal elastic optical modulator where the fast axis direction is fixed. In the pure traveling wave mode, the fast axis of the elastomer modulator rotates at high speed, so a new support method is required. By establishing a damped string vibration model and analyzing the three-dimensional vibration displacement of the surface of the elasto-optical crystal at different fast axis angles, a central support method based on the pure traveling wave modulation mode of the elasto-optical modulator is proposed. Then, using the theory of polarization optics, the Mueller matrix of each device is obtained according to the polarization properties of different optical devices, and the Stokes vector of the emitted light is calculated. It is obtained that when the photoelastic modulator is in pure traveling wave modulation mode, there are only double frequency signal. Finally, the pure traveling wave modulation mode is verified experimentally. The signal generator and amplifier are used to provide amplified driving signals to the two piezoelectric drivers. When the photoelastic modulator reaches resonance stability, the detector is used to collect the emitted light, and the signal is processed and displayed and collected on the host computer, and the collected light is the signal undergoes Fourier transformation to obtain the frequency domain signal of the emitted light. The results show that the detected signal has a direct flow and a double frequency, thus verifying the pure traveling wave modulation mode of the elasto-optical modulator. It also proves that the central support method can ensure that the resistance experienced by the elasto-optical modulator after reaching resonance is uniform and minimal, to achieve the best support effect. In the next research, from the perspective of application, we will combine PEM related technology with ellipsometry, and use the Bessel function and the Mueller matrix of each device to obtain the Mueller matrix of the sample, realizing the sample ultra-high-speed measurement of thickness and associated polarization information.

Supercontinuum generation requires suitable material platform with a high third-order optical nonlinearity and a broad transmission window. In terms of these, chalcogenide glass has advantages such as a wide transmission range, high linear and nonlinear refractive index, and low two-photon absorption, making it promising for near- to mid-infrared nonlinear optical applications. However, the fabrication process of chalcogenide glass optical waveguides still needs to be optimized, and how to excite the supercontinuum using the pumping sources that are cheaper and commercially available is still a challenging issue. Therefore, there is an urgent need to develop chalcogenide-based on-chip light sources that are pumped by 1.55 μm laser.In this paper, we used commercial software (COMSOL Multiphysics) based on complete vector finite components to simulate the dispersion properties of the strip As2Se3 waveguide using SiO2 as a bottom cladding and air as a top cladding layer, the zero dispersion wavelength can be shifted to 1.55 μm in the waveguide with a width of 800 nm and height of 500 nm, where the effective refractive index of both TEo and TMo modes are kept at more than 2, indicating that both of the modes can be well confined in the waveguide. We also calculated the wavelength dependence of the area of the effective modes and nonlinear coefficients, and found that, the form one increases while the latter one decreases with increasing wavelength.Then, we explored the fabrication process of chalcogenide waveguide based on As2Se3. We employed thermal evaporation to prepare As2Se3 thin films on thermally oxidized silicon wafer with a 3 μm thick SiO2 layer, and then vacuum annealed the films at 150 ℃ in the vacuum in order to reduce the defects of the films and decrease the optical loss of the film. The As2Se3 stripe waveguide was patterned by the electron beam lithography (RAITH e-LINE Plus). Optical microscopy and scanning electron microscopy observation showed that the waveguide has a smooth side and wall profiles. We further used the cutting-back method to measure the optical loss of the as-prepared waveguide. Each facet of the waveguide has a loss of 2.4 dB, and the propagation loss of the waveguide is 1.44 dB/cm.Finally, we investigated supercontinuum generation spectra in As2Se3 striped waveguide pumped by 1.55 μm fiber laser with a pulse width of 579 fs. The waveguide length is 10 mm and the pump power is from 30 W to 70 W. Both simulation and experimental results showed almost identical results. While the pump wavelength was in the abnormal dispersive region, the supercontinuum spectra became broad due to the four-wave mixing and soliton nonlinear effect. However, when the pump wavelength was shifted to the normal dispersive region, the supercontinuum spectra can be symmetrically spanned due to the self-phase modulation with much better coherence. On the other hand, with increasing pump power, the supercontinuum spectra became broad and flat. It was found that, self-phase modulation played an important role in the broadening of the supercontinuum at a low pump power, while the splitting of the higher order solitons in higher pump power began to make contributions to the broadening of the supercontinuum spectra. The supercontinuum spectrum was from 1 200 nm to 1 800 nm with a maximum width of 600 nm in the As2Se3 waveguide pumped by 70 W laser power, which is comparable to the best results so far reported in the literature.The present results demonstrated that As2Se3 waveguides with high nonlinearity and tunable dispersion have huge potentials in the development of a cheap on-chip supercontinuum source pumped by 1.55 μm laser.