Because of phase compensation instability (PCI), the thermal blooming phase compensation issue is more and more concerned. The frequency-weighted deformable mirror (DM) eigen modes are generated by orthogonalizing the coupling matrix between DM actuator influence functions. The numerical model of wave-front reconstruction algorithm based on DM eigen mode is established, and the adaptive optical (AO) system based on this wave-front reconstruction algorithm for correcting thermal bloomed wave-front is numerically simulated. Results show that compared to the direct slop method, the DM eigen mode reconstruction method can change the spatial frequency of correction phase through eigen mode chosen, eliminate the effect of high spatial frequency on thermal blooming correction, stabilize the AO system close loop control, and improve the system correction thermal blooming performance.

Due to the new requirements of post-launch calibration, the global calibration-site network database is developed by Oracle 10g and Visual C++. Key technologies including database architecture, multi-source data processing, access control model and database optimization are considered. 103 optical calibration sites between 72°N and 75°S are selected. There are 15 kinds of site types and 7 types of site parameters. The approaches to achieving some parameters are given. The range of site reflectivity is between 0.01 and 0.90. These sites are suitable for post-launch calibration of solar reflective bands. The database has the fundamental functions of management, query, maintenance and application. Finally, the application methods of site data are introduced.

A new method about how to classify different aerosols by lidar measurements is proposed. Two lidar equations including the optical parameters about background aerosol and cloud are built. The inversions about the two lidar equations are given to classify the background aerosol and cloud. The lidar signals related to two different aerosols, with two different extinctions to backscatter coefficient ratios (Saer1,Saer2), are simulated. The inversions about the two simulated lidar signals are obtained. The background aerosol and cloud are measured by lidar, and the two different aerosols are obviously classified according to the analyzed measuremental results by using this method. The simulation and measuremental results verify the effectiveness of the method for aerosol classification.

Knowing the distribution of sky luminance at any time is the foundation to make full use of natural light and realize intelligent lighting. Based on the CIE 15 sky types and the sky luminance formula, calculation methods of the parameters in the sky luminance formula are studied. Using this method, we only need to know the local latitude, date and sky type that the sky belongs to, and the distribution of sky luminance at any time can be calculated. Based on the existing reliable measured data of sky luminance distribution, the calculated values of the sky luminance distribution and the measured values are compared, and the differences between the calculated and measured values are analyzed. The results show that, the calculated data of the sky luminance distribution are in good agreement with the measured data, so the measured data can be replaced by the calculated data as important data for the energy-saving light regulating.

By using the plane-wave ultrasoft pseudopotential method within the generalized gradient approximation, the structure parameters, band structure, electronic density of states, magnetic moment, and optical properties of Na+ doped tetrahedral Co(1-x)NaxCr2O4 system are fully investigated. The results indicate that Na+ is easier to enter tetrahedral sites (Co) in comparison with octahedral sites (Cr) with ion doping fraction of 0.125 for Na+. With the increase of ion doping fraction of Na+ in Co(1-x)NaxCr2O4 system, the lattice parameters become larger as in the usual case, on the contrary, the magnetic moment and band gap become smaller. Meanwhile, the Fermi level moves deeper into the valence band region. In addition, the absorption spectra of Co(1-x)NaxCr2O4 shift to red in the low energy region, and a strong absorption in the low energy region is obtained. This indicates that the doping Na+ can substantially improve the absorption of visible light and enhance catalytic efficiency of CoCr2O4.

To establish accurate response model of time delay integration charge coupled device (TDI CCD) image system, the main parts are analyzed in detail, such as CCD sensor, amplifier circuits and video processing circuit, according to the flow of signal processing. The response model for the actual system is established in theory based on the flow processing. The noises of dark current, video processing circuit are tested on a spatial TDI CCD image system. And so is the radiometric calibration under conditions of different parameters and illuminations. The image data of experiments is analyzed. An approximate formula and a precise formula are achieved by linear polynomial and quadratic polynomial of the least square method. The goodness of fit for linear and quadratic polynomial shows that R2 reaches 0.992 and 0.9998, respectively. The radiation character of ground targets can be acquired by the response model. And the choice of reasonable working parameter can also be decided according to the model. The experimental results show that the response model of image system is accurate and the working parameters are reasonable, which meets the demand and improves the efficiency of on-orbit spatial camera.

A high-efficiency grating coupler is designed to couple a planar waveguide and a single-mode fiber. An improvement in fiber coupling efficiency is obtained by using nonuniform diffraction gratings whose grating grooves consist of subwavelength structures with different duty cycle, which can better match the diffracted field profile to that of the Gaussian fiber mode. By optimizing the thickness of the buried oxide layer and integrating a gold bottom mirror, the directionality of SOI grating coupler can be increased. The coupler is optimized using eigenmode expansion-based simulations. A peak coupling eficiency of 93.1% at 1550 nm and 3 dB bandwidth of 82 nm are achieved.

A fiber-optic Mach-Zehnder interferometer (MZI) based on single-mode -multimode-thin-core-single-mode fiber structure is proposed and demonstrated for measuring refractive index and temperature simultaneously. The multimode fiber (MMF) and the thin core fiber-single mode fiber (TCF-SMF) spliced point serves as mode coupler. When the light is launched into the MMF through the lead-in SMF, at the MMF-TCF spliced point, the core mode and cladding modes are excited and propagate in the core and cladding region of the TCF respectively. The optical path difference can be produced between different modes propagating within the TCF. Then, at the TCF-SMF spliced point, the excited cladding modes coupled back into the core of lead-out SMF interfere with the TCF core mode. When the surrounding refractive index (SRI) and temperature change, the transmission spectrum of the sensor shifts. On this basis, the simultaneous measurement of SRI and temperature can be completed by monitoring the dips with different interference orders. The intermodal interference mainly occurs between the core mode LP01 and the cladding mode LP16 based on a fast Fourier transformation analysis for the transmission spectrum of the sensor. The sensitivities of the sensor response to the change of SRI and temperature are theoretically achieved. The SRI and temperature theoretical sensitivities of the interference dips at 1535 nm and 1545 nm are -55.90 nm/RIU, 0.0501 nm/℃, and -56.26 nm/RIU, 0.0505 nm/℃, respectively, where RIU is refractive index unit. The responses of the sensor are experimentally studied at the SRI range from 1.3449 to 1.3972 and temperature range from 20 ℃ to 90 ℃, and the sensitivities -53.03 nm/RIU, 0.0465 nm/℃ and -54.24 nm/RIU, 0.0542 nm/℃ for the two selected interference orders. The theoretical analysis of the sensor is in good agreement with that obtained in the experiment. This kind of sensor can offer attractive applications in biomedical sensing.

Electrostatic voltmeter plays an important role in the measurement of atternating current (AC) and direct current (DC) high voltage. In order to achieve highly precise measurements in a wide range, an electrostatic voltage sensor using Fabry-Perot (FP) cavity interferometry principle is proposed and fabricated. The measurement electrodes consist of a sensor electrode and a high voltage electrode. FP cavity of the sensor is formed by optical collimator and polyester film aluminized outside. When the high voltage electrode is applied, uniform electric field is produced between polyester film and high voltage electrode. Under the pull of electric field, the shape of polyester film is deformed and the length of FP cavity changes, causing the output spectrum shift of the FP sensor. Phase demodulation method is used to obtain high voltage applied to electrode and realize the electrostatic voltage measurement. The experimental results show that the sensor can measure DC voltage and AC root-mean-square voltage in 5~16 kV. The measurement accuracy is 1.21% of 5 kV to 10 kV and 0.61% of 10 kV to 16 kV. The sensor satisfies the requirement of high voltage measurement.

Based on the formula of beam width of Gaussian-Schell model beam in strong turbulence, the expression of wander variance for a horizontal-path propagating partially coherent beam in the atmospheric turbulence is derived using the general expressions of the beam wander variance models of Andrews and Philips, and the spreading and wander of a partially coherent beam through the whole atmospheric turbulence are discussed. The results show that the partially coherent beam is less affected by turbulence than the fully coherent beam. The smaller the initial beam radius of partially coherent beam is, the more seriously the beam may be affected by turbulence. Within the short propagation distance, the beam wander caused by different wavelengths has little difference, which can reduce as the initial beam radius increases. When the propagation distance is further than 2 km, beam wander in both strong and weak turbulences is related to the wavelength, which is more obvious in strong turbulence. When the spatial coherence length is greater than 0.005 m, it has little effect on the beam wander in propagation distance of 10 km.

In order to study effect of the metal coating on the macrobending loss properties of a fiber loop, two mathematical models of the thermal stress and the associated photoelastic effect of the metal coated fiber loop are established. The thermal stress coefficients and thermal stress dependent refractive index coefficients of the fiber loop with metal coating are calculated. Impact factors of the thermal stress coefficients Kθt, Krt and the thermal stress dependent refractive index coefficient Kn are simulated. The results indicate that Kθt is much greater than Krt at the same circumstance. Consequently, the metal coated fiber loop mainly suffers the annular thermal stress and the radial thermal stress can be ignored. The thermal stress and its induced refractive index change alter with the reference radial position and thickness of the coating rather than the bend radius of the loop. When the thickness of the metal coating increases from 0 to 2000 μm, Kθt and Kn both undergo a process of a sharp increase, and than transfer to a slow growth and tend to a stable value. Since Kn is negative, refractive index decreases as the temperature increases. The presented models are feasible to explain that refractive index of the fiber decreases with the increase of temperature, thus altering the macrobending loss of the metal coated fiber loop.

The performance of free-space optical communication (FSO) with the combined effects from scintillation effect and pointing errors under Gamma-Gamma atmospheric turbulence is investigated. Assuming FSO system uses intensity-modulation/direct detection (IM/DD) with on-off keying (OOK), the novel closed-form expressions of bit error rate (BER) and outage probability for FSO system are derived. How the performance is affected by the atmospheric turbulence and other parameters such as the normalized beamwidth, the average transmitted optical power, the normalized jitter, signal-to-noise ratio is researched. Numerical simulation is further provided to verify the derived analytical expressions. The results show that optimizing the beamwidth can achieve the minimum BER for a given average transmitted optical power.

An adaptive and precise chromatic dispersion (CD) estimation algorithm with a large dispersion monitoring range is proposed based on a two-stage structure for long haul coherent optical communication systems. A coarse estimation of chromatic dispersion is obtained by employing the auto correlation of signal power waveform (ACSPW). Afterwards, a precise CD value can be estimated by using the modified constant modulus (CMA) scheme. Simulation results show that the measured error value is less than 35 ps/nm by using the proposed algorithm, and the accuracy is improved about four-times compared to the conventional ACSPW algorithm. When the reference error rate is 10-2, the power penalty compared to the ACSPW algorithm is improved by 8 dB.

An approach of manipulating micro-particles based on the theory of power-exponent-phase vortices (PEPV) is demonstrated experimentally. Phase holograms are generated to produce PEPVs with different topological charges and exponential powers. The holograms are displayed sequentially on a spatial light modulator (SLM) for modulating the incident laser beam. The modulated light beam is Fourier transformed by a lens, and then filtered by a pinhole. The selected diffraction order of the beam is focused on the sample stage of an inverted optical microscope. The experimental results verify that the PEPV beam can be used to optically transport micron-sized particles directionally. The beam is found to possess a unique function in the transportation and collection of micro-particles, and can have extensive practical applications in many fields.

Scale-invariant feature transform (SIFT) is one of the most robust and widely used local feature descriptor for image registration, however, the computational complexity of its key point descriptor computing stage is quite expensive and also the dimensionality of the key point feature vectors is relatively high. For speeding up the SIFT computation, a novel sparse random projection (SRP) based algorithm, namely SRP-SIFT, is proposed by combining SIFT with sparse feature representation methods from the compressive sensing theory. Accordingly, L1 norm is introduced to compute the similarity and dissimilarity between feature vectors used for image registration. The experimental results show that the proposed SRP-SIFT algorithm is much faster than the standard SIFT algorithm while the performance is favorably comparable when performing complex structured scene image registration applications.

In a line structured light measurement system, the accurate extraction of the light stripe centers is one of the key factors affecting the accuracy of the entire system. For the problem of light stripe center extraction in optical measurements in complex environment with high reflection, a multi-scale analysis based method that realizes high-precision extraction of light stripe centers is proposed. The skeleton algorithm is applied to determine the initial centers of the laser stripe, and the mean square deviation σ of the Gaussian kernel is determined based on the width of the light stripe at each initial center. Multi-scale image convolution is carried out to determine the optimal σ, in order to further improve the accuracy of extracting light stripe center. Interlinkage of the light stripe centers is finished. The results show that the method is of high noise immunity, and can achieve high-precision results when the width of the light stripe changes sharply.

Auto-focusing is one of the key issues in the non-mydriatic fundus camera, a fine and rough combined auto-focusing method is presented after analyzing imaging principle of the fundus camera and the retinal image characteristics. Inscribed square fixed focusing window selection method combined with characteristics of fundus image field is presented, and Robert gradient function is used to realize the rough focusing. The focusing window for fine focusing is selected through auto-focusing window selection algorithm based on local entropy, and image sharpness evaluation function based on Zernike orthogonal moment with 9 pixel×9 pixel mask is presented to realize the fine focusing. The experimental results show that the focusing window method based on inscribed square is more stable, and proposed image sharpness evaluation function for fine focusing has better sensitiveness and realtime performance.

In order to explore the characteristic index which can correctly reflect the imaging performance of synthetic aperture systems, the maximal and minimal fill factors, cut-off frequencies, cut-off energy ratios as well as the correlation coefficients of three typical arrays with six apertures are calculated and compared. It is revealed that the imaging quality is determined by the distribution of low and mid-band modulation transfer function (MTF) spectrum. Based on the discovery, a weighted frequency energy curve which takes the frequency magnitude and distribution into consideration is proposed to precisely reflect the difference in imaging quality of various arrays. To maximize the mid-band energy of MTF, the pupil structures of the three arrays are optimized and the corresponding center-gathered arrays are obtained. The experiment results demonstrate that the imaging qualities of the new arrays are dramatically better than those of the original arrays, and the fill factor ranges can meet the common design demand as well.

Fiber point diffraction interferometer meets the accuracy of optical test for extreme ultraviolet lithography (EUVL). Wavefront reference source which emits circularly polarization state light can enhance the contrast of interference fringes and reduce the astigmation of wavefront reference source. The principle of phase-controlled polarization controller is analyzed by Mueller matrix and found to obtain circularly polarization by only using the first two control channels. A polarization control system has been designed, and the light intensity is analyzed after propagating from the polarization control system by Jones matrix. The control voltage of the first two control channels are obtained. A polarization control system is built and a circularly polarization light is achieved. The error between theory and reality is about 7.5%, which is verified by analyzing the first two control channel before polarization control test. The polarization of wavefront reference source is controlled into circularly polarization quickly, thus the problem of polarization control is solved for fiber diffraction interferometer.

A high-speed scanning real-time stroboscopic laser fringe-pattern projection system is designed. A high-speed rotating polygon mirror and a line-structured laser cooperate to produce stable and unambiguous stroboscopic fringe patterns. The system is realized by using field programmable gate array (FPGA) to monitor photoelectric-detector signal and control the output modulation signal of laser accurately in real time. The system combines the overall projection of grating with the high accuracy of the line-structured laser light source. The projected fringe patterns have high refresh rate and high precision. In addition, the intensity, frequency, pulse width and phase shift can be controlled in real time by dynamic programming. A small size device is measured by using the proposed system, and the corresponding accurate phase and characteristic points that can show the three-dimensional shape are obtained. The proposed system shows a broad application prospect for fast three-dimensional shape precision measurements, particularly in the industrial field of three-dimensional online detection for precision devices.

In order to meet digital, high-accuracy detection requirements, a measuring system of infrared sight zero variable quantity based on charge coupled device (CCD) machine vision is designed. A new zero variable quantity measuring model is established. According to measuring system technical indicators and requirements, the off-axis parabolic collimator and pinhole target are designed. To reduce infrared sight zero variable quantity measuring error caused by camera tilting, a camera pose adaptive correction model is established, which is firstly applied to infrared sight zero variable quantity measuring. An image interpretation software is designed based on visual studio software development platform, using Gravity method to locate spot center of target image, and using Zernike orthogonal invariant moments to classify pixel on the edge. A functional prototype is successfully developed, processing equipment is tested after adjustment. The results show that its detection uncertainty is better than 0.02 mil, which can avoid measuring error caused by camera tilting and satisfy digital, high-accuracy test requirements on infrared sight zero variable quantity.

Dynamic accuracy appraisal method of optical theodolite, called ‘Hard method’, is rough and complex in engineering. Its appraisal result is inaccurate, poor in reliability and imperfect. For these reasons, a convenient dynamic accuracy appraisal method of optical theodolite is proposed, called ‘Soft method’. Its mathematical model and solution method are deduced. Through simulation, comparative calculation with these two appraisal methods is carried out. The results show that for dynamic accuracy appraisal of optical theodolite, ‘Soft method’ takes greater advantages in accuracy and reliability. In addition, the method is easier and more conducive to engineering applications.

The optical transfer function is the important parameter to evaluate the image quality of optical system. Based on the working property of one new type aviation lens shutter designed for the digital aerial photograph camera, the analysis of influence on the optical transfer function is presented. The lens shutter can change the optical pupil shape of the camera′s optical system in the processing of control exposure, which means the point spread function is changed. Thus the optical transfer function is also changed. The relationship between the variety of aperture stop and the optical pupil function is built up by taking the optical system as the spatial frequency filter and adopting the Fourier transfer method and scalar diffraction theory as the theoretical foundation to analysis the influence of the shutter in the working period on the optical transfer function. Through the comparing analysis of the calculation and measurement results, they show that the maximum absolute error is 0.196 and the maximum relative repetitiveness. Furthermore, the design decreases the time ratio occupying whole error is -0.274 for the optical transfer function, which has better accuracy and exposure time for the beginning stage of shutter and the closing stage of shutter. It improves the comprehensive transfer function of system, which provides the theoretical reference for the optimization design of center shutter.

The registration for free viewpoint measurement highly improved the efficiency of three-dimensional measurement, in order to improve the robustness of three-dimensional mapping between viewpoints, a modified method for mapping stitching with high stability is proposed. The viewpoints is coincided via image features. Spatial points are calculated through the phase positions. Aiming at those image features without phase positions, the interpositions of adjacent points are used to take the place of these points, so that effective mapping points between different viewpoints are virtually reconstructed. The rigid transformation is calculated by using unit quaternions. Experimental results show that this method can improve the number of the feature points by 20 percent and the robustness of mapping stitching.

Because the tradition differential plane mirror interferometer (DPMI) has the disadvantages of complicated structure, many optical components and difficulty for adjusting, a novel differential plane mirror interferometer is proposed. Due to its diagonal symmetry of the two frequencies beams, this system has a good stability with environmental variation and a high resolution. With this special arrangement and the use of some additional optical components, the measurements of yaw angle, small rotation, straightness become easy to implement. Experimental result shows that the displacement drift of this system is under 1 nm in the static measurement, while the Michelson interferometer system is more than 10 nm under the same condition. The angular interferometer based on this new structure, with electronic interpolation of 2π/516, has a measurement resolution of 0.024 μrad.

The vignetting caused by the external occulter and support pylon of externally occulted white light coronagraph is analyzed and calculated. The coronagraph is with a field of view of 2.5~15 R⊙ (Sun Radius), a resolution of 14 sec/pixel, an aperture of 30 mm and an effective focal length of 200 mm. An analytical expression of the vignetting as a function of the distance between external occulter and objective is obtained. The vignetting figures at different distances are acquired by simulation. It is shown that the longer the distance is, the smaller the vignetting. The theoretical results are verified by actual experiments with proposed prototype of the coronagraph. The coronagraph image of target is corrected by vignetting compensation, and the image quality is improved greatly.

A high-linear bias-free polymer Y-type coupler electro-optic (EO) modulator is proposed, which consists of Y-type splitter, Y-type combiner, two-section EO region consisting of a pair of push-pull poled waveguides, and a microstrip line electrode. Device structure is proposed and its parameters are optimized. Using Fourier transformation on the applied electric modulation signal and combing the transfer function of the device, a novel formulation technique is presented to model and characterize the device′s static and dynamic performances. Formulas and expressions are derived, with respect to state function, static response, modulation response, third-order intermodulation response, etc. Calculation and analysis results indicate that, the half-wave voltage of the modulator is about 2.69 V, and the 3 dB modulation bandwidth is about 143 GHz. As the modulation coefficient is within the range of 1%~10%, the suppression degree of the fundamental signal on the third-order intermodulation distortion signals is as high as 60 dB~90 dB. The proposed theory and related formulations can also be used to the design, modeling and analysis of a similar device based on Y-type coupler structure.

The main drawbacks of the spontaneous Raman scattering is its poor efficiency due to small Raman scattering cross sections and the interference with radiations from the laser when it is used to measurement actual combustion parameters. To overcome these drawbacks, XeF(C-A) laser is used as excited source in spontaneous Raman scattering research. Some parameters of the XeF(C-A) laser is optimized for adapt to the need of spontaneous Raman scattering. The experimental setup is built, which is used to measurement the mole fraction of components in the atmosphere. The advantages and disadvantages of spontaneous Raman scattering excited by different lasers are compared. The result shows that the XeF(C-A) laser with high energy, long pulse width and long wavelength is very fit to be used as spontaneous Raman scattering light source.

In high power laser diode (LD) end-pumped solid-state laser, due to the complicated interaction between pump optical field distribution and thermal effect, the method of analysis thermal effect used in low power cannot be used, or leads to large error. In the light of the above, the concept of iteration used in calculation method can fully consider the interaction between pump optical field distribution and thermal effect. So, the interaction in some typical LD end-pumped solid-state laser is analyzed, and the calculation error without considering the interaction is studied. At the meanwhile, by comparing abortion length of solid-state laser material with its effect focal length, a parameter K is put forward to measure intensity of the interaction, and it can be used to judge whether considering the interaction or not. The results show that when the parameter K is less than 0.1, the influence of the interaction is below 3 percent.

By employing laser diodes end-pumped dual-longitudinal-modes Nd:YVO4 microchip laser as seed source, dual-end-pumped Nd:YVO4 traveling wave amplifier as power amplifier, a dual-frequency laser with larger frequency separation and high power output is obtained. In amplification process, spectral matching effects are analyzed. The results show that, with the increase of the seed light power, the overall magnification shows a decreasing trend, and the detail shows a wavy trend. Due to the limiting of amplifier gain bandwidth, the frequency separation of amplified signal is less than that of the seeds. When the pump currents of microchip and amplifier are 14.5 A and 40.0 A, respectively, the amplified output signal power is 2.38 W and the frequency separation is 47.7 GHz.

A novel encoding method is proposed for precise binocular three-dimensional (3D) measurement of colorful objects. According to the combination of the red-green-blue (RGB) model and the spectrum analysis methods, unique visual code values are attached with different colors respectively. The color code pattern is designed based on the principles of obvious change of wavelength, evident difference in color between adjacent color stripes, and unique code values for neighbors. A color calibration optimization algorithm is proposed to achieve color compensation and eliminate color confusion during the 3D measurement processing. A series of measurement experiments are performed to acquire the 3D shape of the colorful objects. The experimental results show that the 3D shape of the colorful objects can be easily and fast obtained by using this novel encoding method.

Based on the optical antenna theory, the emission quenching of tris-(8-hydroxyquinoline) aluminum (Alq3) by silver nanoprisms is investigated by experiments and numerical simulations. The emission quenching is attributed to the coupling between the emission of Alq3 and the in-plan electric quadrupole resonance of silver nanoprisms. In experiments, the quenching factor is 0.25~0.5. As the density of silver nanoprisms on the substrate increases, the dimers and trimers increase. It enhances the near-field electric field, improves the excitation efficiency and decreases the quenching factor. Numerically, the quenching factor is about 0.44. It is agreement on experimental results. The study is significant to apply the nanoprism for molecular sensor and surface-plasmon-assistant image.

By using the first principle pseudo-potential plane-wave method based on the density function theory (DFT), the geometrical structure, electronic structure and optical properties of β-FeSi2 with doping Ac are calculated and analyzed. The calculated results of the geometrical structure show that the lattice constants a, b and c change, the volume of lattice expands. Electronic structure calculation indicates that the Fermi energy moves to conduction band, the band structure is still quasi-direct bandgap, which becomes narrow obviously. The density of state near the Fermi energy level is mainly composed of Fe-3d and Si-3p, Ac-6d only devoted to a small part. Optical properties calculation indicates that the static dielectric constant ε1(0) increases. The peak of the imaginary part of dielectric function ε2 decreases and moves to a lower energy. The refractive index n0 increases significantly and k moves to a lower energy. Optical absorption coefficient increases. The average reflective effect has little change. These results offer theoretical data for doping of β-FeSi2.

Based on the photonic local feature of photonic crystals, one-dimensional mirror air gate photonic crystal structure is proposed. Due to the introduction of mirror structure, a defect cavity is formed in the middle of the photonic crystal, and then the resonant transmission peak can be obtained in the forbidden band of transmission spectrum. The transfer matrix method is used to establish the relationship model between the resonant transmission peak and the structure parameters of the photonic crystals. Using the rectangular air gate photonic crystal structure, the dynamic monitoring of the detected gas sample parameters can be achieved from the shift of the resonant transmission peak. Taking formaldehyde as the detected sample, the Q value and sensitivity of the refractive index sensor are analyzed. The simulation results show that the Q value can attain to 1739.48 and the sensitivity can attain to 816.67 nm·RIU-1 (RIU is refraction index unit), which demonstrates the effectiveness of the sensing structure. The structure can provide certain theoretical reference for air pollution monitoring and gas component analysis.

In order to investigate the feasibility of fiber-guided 2.013 μm Q-switched thuliumYAG lasers as one microsurgical scalpel, dissection performance of 200 μm core diameter fiber-guided thuliumYAG lasers operating at 1 kHz repetition rate and 400~1400 ns pulse duration on fresh pig kidney tissues, is researched under different pulse energies and dissection velocities. One professional camera and one optical microscope are used to capture the macro-histological tissue surfaces and the micro-histological craters, respectively. A scientific standard software is used to analyze the experimental data. The experimental results show that the dissection effect is not obvious for higher dissection velocity under the same low energy level. However, it is obvious for higher energy under the same dissection velocity. The fiber-guided high repetition rate Q-switched thuliumYAG lasers will be expected to be used in clinical operation as a microsurgical scalpel.

Characteristics of the intensity fluctuation of the light back-scattered by flowing particles are studied. The influence of moving particles on back-scattered light is divided into phase modulation and amplitude modulation, and a new model is proposed that includes the total information of both axial and lateral components of velocity. Based on the new model, the two velocity components can be calculated according to the Doppler frequency shift and the transit time derived from the detected light intensity signals. The proposed model is experimentally verified using polystyrene particle suspension flow.

A novel fundus camera with liquid tunable lens (LTL) to compensate the ametropia of human eye is designed and developed. The formula for the power of the LTL related to the diopter of eyes is deduced by Gaussian brackets method. The paraxial optical system of the fundus camera with ophthalmophantom is calculated and modeled. To enable the imaging beam to pass through the LTL without obscuration, the eye pupil and the LTL are conjugate with each other with respect to the lens system between them, and the lens system should have a magnification approximately to 1. To eliminate the stray light, the light source and the cornea are conjugate with each other in the illumination system, ring-shaped light source combined with polarized light is used. Besides, an analyzer plate is placed after the beam splitter to block the light reflected from the lenses and cornea. The fundus camera has a field of view of 50°, working distance of 40 mm, and overall length of 220 mm. Experiment is carried out to demonstrate the diopter compensation capability of the system, in which fundus images of ophthalmophantom at different diopters are captured, and these images are compared with those of the system where no LTL is adopted. The results show that by means of using LTL, the camera can adapt to eyes with diopter range from -10 D to +10 D (1 D=1 m-1). This compact system with LTL can remarkably simplify the optomechanical structure while maintaining a good diopter-adjusting performance.

Antarctic Dome A is considered to be the most outstanding astronomical photometry and observation site on earth, particularly in the infrared. To take full advantage of the unique advantages for astronomical observation, meet the needs of exoplanet observations and provide experience for the future development of larger antarctic telescopes, the construction of 1 m visible/infrared survey telescope is proposed. By occultation method to detect exoplanets, it should achieve five ten thousandths of photometric accuracy by reducing background radiation,suppressing the self-radiation of telescope is very important. Take 1 m visible/infrared sky survey telescope as an example, the method of suppression of self-radiation is discussed. One meter antarctic visible/infrared survey telescope adopt a direct, simple optical system, but can not be set the cold pupil, suppressing stray light is less efficient. By optimizing the design of the optical system, setting the secondary mirror as aperture, the unique design of the Dewar, secondary baffle and main baffles, the background radiation on imaging surface is 6.8×10-10 W/m2. Through simulation, which is one-fifth of the sky background radiation, the background radiation suppression meets the requirements of astronomical observations.

In order to realize the static and dynamic contrast calibration of the adjustable contrast optical target device for measuring the low-contrast target capture capability of photoelectric tracker, a target sources contrast measurement system is established for researching the relationship between image contrast and optical contrast. The static target sources image contrast is analyzed and the static calibration curve based on the least squares method is obtained. The military standard rules and the static calibration method, according to the dynamic target sources unique “deformation effect” and “gray gradual change effect”, which leads to the problem of lacking uniform and accurate target gray extraction method; discriminant analysis based on mathematical statistical methods is used to classify target gray extraction frame dimensions by different gray values. Then, the scatterplots are applied to visualize the relationship between the extraction frame size and gray distribution, which makes the extraction frame size clear and exclude harmful effects from the above two effects on calibration. Dynamic contrast calibration curves are mapped out under different rates conditions. Experimental results indicate that the accuracy of extraction frame selected is more than 94% and the evaluation parameters of the static and dynamic calibration fitting equations: R2 and R2adj are both better than 99%, calibration precision S is better than 0.006, which demonstrates that the method is feasible and can satisfy contrast calibration demands in the equipment.

A novel heat-release structure with slotted plate is proposed to enhance the heat dissipation performance of high power multi-chip chip-on-heatsink (COH) LEDs. The junction temperature, thermal resistance, fluid field and the performance of heat dissipation are simulated and analyzed by Icepak software under natural convection. The simulation results show that the slotted plate can improve the flow feature of fluid field, increase the surface heat transfer coefficient, enhance the capability of heat dissipation. There is a best pitch between two plates to make the junction temperature and thermal resistance lower under the thermal conduction and thermal convection. And the junction temperature and thermal resistance lower 3.2 K and 1.01 K/W respectively when the input power of each chip is 1 W under the best pitch. For slotted plate, the capability of heat dissipation is enhanced obviously with the increasing of input power for each chip, and it also decreases the weight of plate and reduces the cost.

The transversal and longitudinal intensity and phase distribution of speckle fields in diffraction patterns of random scattering surfaces under vortex beam with different topological charges are simulated. It is observed that the transverse and longitudinal average size of speckle grains is smaller than that of speckle grains produced by Gauss beam passing through the random scattering surfaces, and it becomes smaller with the increase of the topological charge and radius of vortex beam. At the same time, the density of phase vortices becomes larger with the increase of the topological charges and radius of vortex beam in the diffraction region. The speckle sizes can be adjusted by changing the topological charges and radius of vortex beam to trap particle. This result can be used to reduce the noise.

Dynamically controlled photonic bandgap (PBG) is achieved via the electromagnetically induced transparency (EIT) in the one dimensional optical lattices filled with cold atoms driven to the four-level Lambda configuration with spontaneously generated coherence (SGC). When the coupling field is far away from resonance or resonant, two or three well-developed photonic bandgaps can be induced based on spontaneously generated coherence from the two decay pathways. While in the absence of SGC, the probe field is absorbed by the medium, so the PBG around the probe resonance is severely malformed or even cannot be generated. Numerical calculations show that the induced PBG results from the Kerr nonlinear modulation between the probe and coupling field, and by controlling the detunings of coupling field, the two PBGs can be dynamically tuned into three PBGs in this system.

Simplex growing algorithm (SGA) is a kind of effective endmember extraction algorithm for hyperspectral images.In order to solve the high computational complexity problem which arises in the repeating volume calculation for SGA, with SGA that uses hyperspectral spatial simplex volume computation formula (NSGA), two fast implementation algorithms, NSGA algorithm based on matrix factorization (FNSGACF) and NSGA algorithm based on the block matrix determinant (FNSGA), are proposed. FNSGACF uses improved Cholesky decomposition to change simplex volume computation into triangular matrix decomposition, which can reduce the computational complexity and improve the efficiency of the algorithm. FNSGA introduces the idea of partitioned matrix to simplify the computation of the matrix determinant which greatly reduces the computational complexity. The experimental results with the simulated and real hyperspectral data show that these two fast implementation algorithms can perform faster on the basis of keeping results of NSGA and achieve the purpose of fast implementation.

To monitor the in-orbit radiometric performance of multiple satellite remote sensors onboard, a vicarious calibration methodology based on pseudo-invariant reanalyzed benchmark database is presented. Using Dunhuang radiometric calibration site, a homogeneous stable test site, the reflectance-based reference and aerosol real time estimated models are established after analyzing the reflectance spectral and atmospheric characteristics at the site. Meanwhile, the radiometric calibration of ZY-1 02C, ZY-3 and GF-1 remote sensors is carried out using fore-mentioned reflectance-based calibration model. The research results by comparing the calibration results with usual method and ground measured data are validated and discussed. The results indicate that the calibration of multiple remote sensors can be performed based on analyzed data of pseudo-invariant site, and the relative difference is less than 5.0% between radiance based on the calibration results and the predicted radiance with the ground measurements, and the accuracy of new method is the same as usual calibration result. The research results can provide data reference for future calibrating the radiometric calibration coefficients and monitoring the property change of remote sensors.

Stripe noise perturbs image qualities of push-broom-type aerial camera, thus eliminating stripe noise is of vital importance to improve the precision of posterior data analysis. The main sources and the model of stripe noise in aerial images are analyzed and a new destriping stripe noise algorithm based on total variation is proposed. The gain and offset of each pixel are estimated based on quasi-homogeneous regions. The total variation algorithm is utilized and the image is reconstructed by the gradient descent method iteratively. The qualitative analysis results demonstrate that the peak signal-to-noise ratio of the simulated image is improved from 31 dB to 40 dB and the improvement factor of radiometric quality of the real aerial image is improved to 9 dB. Compared with traditional methods, the proposed algorithm can achieve higher inverse coefficient of variation and improvement factors of radiometric quality. Stripe noise can be effectively removed with detailed information of the original image reserved.

Low cost optical network unit (ONU) light sources based on tunable distributed feedback (DFB) laser array using for wavelength division multiplexing-passive optical network (WDM-PON) are fabricated by nanoimprint lithography (NIL) and butt-joint regrowth (BJR). The multi-mode interference coupler (MMI) is used as output device for the monolithic integrated device. The tested results indicate that, the threshold current is less than 10 mA, side mode suppression ratio (SMSR) is higher than 40 dB, tunable range is wider than 10 nm and output power is larger than 0.2 mW.

A new camera self-calibration approach is proposed based on the property of the vanishing points and the aspect ratio of the rectangle′s two groups of opposite sides. This method can calibrate the camera′s intrinsic parameters and identify the aspect ratio of the rectangle, whether known or unknown the character of camera′s sensor, according to twice or triple imaging for the same rectangle, respectively. The equations of the camera′s intrinsic parameters are established via three properties: the first one is that the lines which connect finite points and the same infinite points are parallel; the second one is the harmonic division which consists in the complete quadrilateral; the third one is the identity length-width ratio of the rectangle which imaged sometimes. A correction method of the camera distortion, utilizing which the accuracy of self-calibration correspond to the no distortion situation, is proposed via iterative between the optimization of nonlinear distortion parameters and solving of linear intrinsic parameters, based on constructing a cost function of lines′ imaging. Simulations prove that the calibration algorithm can converge sharply, and the results are not sensitive to image noise. Real imaging tests prove that, comparing with traditional calibration by flat surface drone, this method can reduce foreknowledge conditions, as well as promoting both precision and efficiency of the calibration results.

Nitric oxide (NO) has significant influences on the infrared radiative transferring of hypersonic vehicle and its flow field, but the HITEMP database can calculate NO′s parameters only for 70 K~3000 K and at present the available algorithms for calculating NO′s partition function seldom take the effect of lambda-doubling in electronic ground into account. Therefore, calculation of NO′s radiative parameters with higher efficiency and accuracy is rather significant. According to the product approximation, the total internal partition function is decomposed into electronic, vibration and rotation partition functions. The fact that NO′s X2Π ground state splits into 2 spin components has been considered so as to improve the accuracy. With temperature between 3000 K and 8000 K, the rovibration partition function is rectified. Experiments show that the partition function of the proposed algorithm agrees with total internal partition sums (TIPS) of the HITEMP with temperature between 70 K and 3000 K, with the maximum error being no more than 0.3%. Moreover, the proposed algorithm can calculate partition functions under non local-thermal equilibrium. Besides when compared with the algorithms based on summation at high temperature as well as experiments, the proposed method has high accuracy.

To investigate the feasibility of mental workload assessment by using functional near-infrared spectroscopy (FNIRS), 12 college students are orgainzed to complete N-back and multi-attribute task battery (MATB) tasks with physiological parameter, behavioral performance and subjective scale. The sensitivity and difference of FNIRS parameters of different difficulties are analyzed. FNIRS data of the first, fifth, ninth and tenth channels in dorsolateral prefrontal cortex (DLPFC) area in N-back task and the first, ninth channels in DLPFC area during MATB task are more sensitive to mental workload. In the tasks of 0~2 level difficulty, the oxygenated hemoglobin (HbO) and total hemoglobin (tHb) show greater change as the difficulty increases and lower value change in 3 level difficulty. The results show that the FNIRS signal in DLPFC is the most sensitive area of mental workload in prefrontal cortex (PFC) area. Within a certain range of difficulty, HbO and tHb show larger change as task difficulty level increases, but the change will be opposite when task difficulty beyond a certain level.

Strained InGaAs/GaAs single quantum wells (SQWs) are grown by the low pressure metal-organic chemieal vapor deposition (LP-MOCVD). The experimental results show that the photoluminescence (PL) emission of InGaAs/GaAs SQW can be greatly improved by optimizing the growth rate, V/III ratio and temperature. It is found that the QW structures grown at the growth temperature of 600 ℃ and the growth rate of 1.15 μm/h exhibit better PL emission, stronger PL intensity with higher V/III ratio. The reason why the blue shift phenomenon of PL spectrum disappear when the InGas ratio is higher is explained by a model.

In the eye model involving the angle formed by visual and optical axis, an achromatic element eliminating longitudinal chromatic aberration (LCA) only while maintaining transverse chromatic aberration (TCA) is designed and the eye model of TCA-only is constructed. Furthermore, the actual data of human eye′s higher-order aberrations are introduced into the eye model along visual axis to investigate the interaction between chromatic and higher-order aberrations. Three kinds of individual eye models are constructed to investigate the impact of higher-order aberrations, chromatic aberration (LCA+TCA), LCA and TCA on vision under the photopic condition, as well as their interactions. The results show that for most of the eyes the impact of chromatic aberration on vision is far greater than that of higher-order aberrations and the presence of chromatic aberration further reduces the impact of higher-order aberrations. Among the impact of chromatic aberration on vision, LCA is a dominant factor, and the impact of TCA can be ignored for most of the eyes.