In order to study the transmission characteristics of infrared radiation in fog under multiple scattering effect, the extinction parameters and multi-particle scattering phase functions of 1.064 μm, 3.8 μm and 10.6 μm laser in advection fog and radiation fog were calculated based on Mie theory. A radiative transfer model was established by Monte Carlo method. The effects of the size of the receiving screen, the visibility and the transmission distance on the transmittance were analyzed, and the results were compared with Lambert-Beer law. The results show that when the visibility and transmission distance are both 1 km, the number of particles on the receiving screen of 1.064 μm laser in advection fog increases significantly with the increase of receiving screen side length. The attenuation of laser in radiation fog is less than that in advection fog under the same visibility and transmission distance. 10.6 μm laser has good transport properties in advection fog. The stronger the scattering ability and the higher the forward scattering probability, the more obvious the contribution of multiple scattering to the transmittance. The attenuation characteristics of laser transmission in fog are related to extinction coefficient and scattering coefficient. There is an optimal combination of visibility and transmission distance which maximizes the contribution of multiple scattering to the transmittance.

The multiple random phase screen simulation method is used to simulate the anisotropic turbulent atmosphere and Bessel-Gaussian beam in intensity distribution, the on-axis scintillation and beam wander. The effects of anisotropic turbulence parameters and wave source parameters on the propagation quality of Bessel-Gasuuain beam are analyzed. The results show that the intensity distribution of Bessel-Gaussian beam in anisotropic turbulent atmosphere is related to the off-axis distance. Only the intensity value at the first ring decreases monotonously, while the intensity value at the other secondary rings increases first and then decreases. The on-axis scintillation index of the Bessel-Gaussian beam at close range decreases with the increase of the waveform parameter, and there is a trend of first rising, then falling and then rising with the increase of beam width. This phenomenon is related to the beam width of Bessel-Gaussian beam. The beam wander decreases with increases of the waveform parameter, the number of orbital angular momentum, the wavelength and the beam width. However, at a long distance, its on-axis scintillation index and beam wander effect are opposite to that of near distance, which is consistent with the sudden increase of the width of Bessel-Gaussian beam. The wander effect of Bessel-Gaussian beam in anisotropic turbulent atmosphere is significantly less than that in isotropic turbulence atmosphere, and the result even larger than Laguerre-Gaussian beam at long distance.

The coupling efficiency theory model of the spatial light into few-mode fiber in the different influence factor is established. Takes two-mode fiber for example to study the relative aperture effect on coupling efficiency. When the relative aperture is 0.17, the highest coupling efficiency is 82.96%. The coupling efficiency in the presence of tilt, defocus and random angular jitter is studied, the experiment show that when the lateral offset is 4 μm, the coupling efficiency of two-mode fiber is higher than single-mode fiber about 10.23%, when the axial offset is 125 μm, the coupling efficiency of two-mode fiber is higher than single-mode fiber about 11.24%, when the random jitter amplitude is 5 μm, the coupling efficiency of two-mode fiber is higher than single-mode fiber about 12.1%. Accordingly, the few-mode fiber can inhibit interference factor such as tilt, defocus and random angular jitter when the signal reception.

Based on the surface plasmon resonance effect, the gold-coated Photonic Crystal Fibers (PCFs) with introduction of three different kinds of asymmetric factors with polarization-dependent filter characteristics were proposed. The polarization-dependent filter characteristics were analyzed by the full vectorial finite element method. When the asymmetric factor is only introduced in the fiber core mode, the resonance losses of x- and y-polarized core modes are 5.58 dB/cm and 461.58 dB/cm at the communication wavelength of 1.55 μm, respectively, the resonance loss ratio in two polarization directions is 83. When the asymmetric factor is only introduced in the surface plasmon mode, the resonance losses of x- and y-polarized core modes with the coating thickness of 55 nm are 2.02 dB/cm and 412.91 dB/cm at the resonance wavelength of 1.31 μm, respectively, the resonance loss ratio in two polarization directions is up to 204. The resonance losses of x- and y-polarized core modes with the coating thickness of 19.5 nm are 5.29 dB/cm and 536.25 dB/cm at the resonance wavelength of 1.55 μm, respectively, the resonance loss ratio in two polarization directions is 101.While the asymmetric factors both in the core modes and the surface plasmon mode are all introduced, the y-polarized resonance strength is up to 802.08 dB/cm at 1.55 μm, the corresponding loss in x polarization is only 5.57 dB/cm, the resonance loss ratio in two polarization directions is up to 144. The numerical comparisons show that the asymmetric factors introduced in the surface plasmon mode or both in two modes can obtain much stronger polarization-dependent filter characteristics with high polarization loss ratio. This work is beneficial for the design and application of the polarization-dependent PCF filters and related polarizers.

A tunable multi-frequency optical millimeter-wave signals generator scheme based on optical carrier-suppressed modulation was proposed theoretically. Millimeter-wave signals with tunable frequency multiplication factor can be obtained through the beating of two sideband components of the optical carrier-suppressed signal which are selected by the uniform fiber Bragg grating based on acousto-optic tunable filter. What′s more, in order to avoid the time shift of code effect caused by the chromatic dispersion of the fiber, the baseband data signals are modulated on only one sideband component of the optical carrier-suppressed signal. To investigate the scheme, some simulations have been done. It turns out that optical millimeter-wave signals with frequency multiplication factors of 2, 6, 10, 14, 18 and 22 will be generated. The transmission performance of the downlink of the radio-over-fiber system are also evaluated. Under the situation that the frequency multiplication factor is 22, when the optical millimeter-wave signals modulated with none-return-to-zero data signals of 2 Gbit/s, the eye diagrams are still wide open after transmitting through the fiber of 50km. Meanwhile, the power penalty is only 0.4 dB. The results show that the system with well transmitting performance can meet the requirements of communication.

The correlation between the odd and even time slot outputs of the fiber optic gyro with double optical length is used for the correlation-cancellation processing of gyro zero offset error. To verify the method, the fiber optic gyro with double optical length is at room temperature, with moving average time of 100 s, the per second output biases of odd and even time slot are -0.1°/h and 0.08°/h, after processing of correlation cancellation, the bias is modified and the bias stability is increased from 0.008°/h to 0.002°/h. The correlation counteraction signal processing method is fast, simple and effective, which provides a new idea for the precision optimization of the fiber optic gyro with double optical length.

An automatic aberration compensation method is proposed by combing phase fitting and deep learning in digital holographic microscopy and applications to dynamic observation of living cell morphology. Firstly, in the holography recording plane, the preliminary aberration compensation is implemented by using a digital phase mask, whose quadratic polynomial fitting computation is based on the extraction of reconstructed phase value along central cross line profiles in the field of view. Then, in the holographic imaging plane, the final aberration compensation is completed by using higher-order polynomial digital phase mask that computed with the phase data in the object free region, which is defined by the convolutional neural network. Thus, the phase image of object is correctly and accurately reconstructed. Thanks to the preliminary aberration compensation in the holography recording plane, the complexity of reconstruction in the holographic imaging plane is effectively reduced before the convolutional neural network training. Therefore, a stable deep learning model for phase image segmentation can be obtained on basis of limited data set and the compensation of phase aberration can be achieved without any manual intervention. The experiments are demonstrated by observing the several kinds of living cells, which have different morphological characteristics, with the off-axis digital holographic microscopy. Furthermore, the proposed method is applied to screen the drug resistance of endometrial cancer cells. These experimental results verify the proposed method and show that it can be used to dynamic microscopic observation in biological cell research.

A comfort evaluation model was proposed based on regional contrast, aiming at the problem that the stereo image comfort is difficult to effectively evaluate objectively, combined with the human visual attention mechanism. The region of interest was extracted as the foreground region according to the saliency map and the disparity map. Then, the color spaces of the foreground and background region were quantized, and the regional contrast with the spatial weighted was estimated. The parallax angle and width angle of the foreground area were calculated. Finally, according to the subjective evaluation values, the objective evaluation model was obtained by fitting the curve with least-square method. Comparing the D+W model, the Pearson correlation coefficient and the Kendall correlation coefficient of the model prediction value and the subjective evaluation value are 8.1% and 3.9% higher respectively than the original model. The average absolute value error is reduced by 13%, and the root mean square error is reduced by 22.1%. The experimental results show that the model has better universality and the result is closer to the subjective evaluation value.

Four-direction weighted least squares phase unwrapping iterations algorithm is proposed based on regional mask filtering and the method of quality map leading weigh to solve the problem that interferometric synthetic aperture radar interferogram is difficult for phase unwrapping due to local noise, shadows or stripe breaks, which result in residual focus and unreliable data patches. Firstly, the noise patch region is masked and filtered. Therefore the real phase information is preserved and the error propagation is prevented effectively. Then, the four-direction least-squares iteration method, which can redefine the weight value by using the quality map method which can describe the maximum phase gradient and the change of phase derivative, is used to fill the mask region to suppress the error propagation, increase the computing speed and improve the over-smoothing effect. Simulation and real data experiments show that the proposed method has high unwrapping accuracy and can restore the original phase of the local patch of interferometric synthetic aperture radar interferogram. Compared with the traditional least squares method, it has the advantages of larger bandwidth of the difference equation matrix, better filling effect, less number of iterations and higher accuracy, which can solve the difficulty of interferometric synthetic aperture radar image unwrapping caused by noise concentration.

A method based on Fabry-Perot (F-P) interferometer is proposed to detect the displacement of the micro-cantilever of atomic force microscopy. A hemispherical F-P cavity composed of a spherical mirror and a micro-cantilever is designed. A single frequency laser is used as the light source. The laser beam is reflected multiple times in the hemispherical F-P cavity and returned to the original path to form an interference. According to the principle of multi-beam interference, the relationship between the interference intensity and the cavity length has been determined and the deflection of the micro-cantilever has been calculated by using the intensity demodulation method. Finally, a micro-cantilever displacement detection system has been built. The experiment obtained a linear fit of 99.9% in the working range of 30 nm, and the minimum displacement resolution of the micro-cantilever was 0.26 nm. The experimental results are consistent with the theoretical analysis, which proves the practicability of the system.

It is demonstrated that an ultranarrow linewidth laser is recovered after transfer through a 100 km fiber link. The fiber link consists of two 50 km spolled fibers cascaded by a repeater station where a transceiver laser is phase-locked to the transferred light of the 50 km fiber with tracking precision of 3.5×10－19. To maintain the high spectral purity, two fiber noise compensation modules are employed to compensate for the fiber-induced phase noise in each 50 km fiber. The cascaded scheme enables a large dynamic range for the noise compensation. The fractional frequency instability for the stabilized 100 km fiber is 5.9×10－17 at 1 s averaging time, reaching 6.8×10－19 at 10 000 s. The ultranarrow linewidth laser is recovered at the remote end of the 100 km fiber with additional linewidth of 1 mHz.

In order to acquire characteristic of the output spectrum in nitrogen diluted combustor driven continuous wave deuterium fluoride laser, the spectrum analysis was accomplished basd on Z-model unstable optical resonator, which used Fourier infrared spectrum analyzer measuing scatter of the reflector mirror in out optical path. The results show that the output lines of nitrogen diluted DF laser transfer to long wavelength, and 3P10～3P13 lines with wavelength larger than 4.0 μm are brought out efficiently. Also, the transition lines of each vibrational energy level take on higher rotational quantum number. The output spectra of DF laser compete intensely existing in self and different band, and cascade effect appears among them. The distribution of DF laser output spectra can be regulated partly by adjusting the combustor oxidant excess index. It satisfies pneumatic performance with excess second fuel, and the distribution or output spectra is affected faintly with the appropriate second fuel ratio range. The results have a reference to research and application of the combustion driven continuous wave DF laser.

A hybrid technology combined ion beam etching and femtosecond laser machining was proposed for solving the problem of high surface roughness when processing of hard materials by femtosecond laser machining. First, silicon carbide micro/nano structures were fabricated by femtosecond laser machining. Then, the silicon carbide micro/nano structures were etched by ion beam etching. Ion beam etching can adjust the width and depth of the line structure, and reduce the surface roughness of the structures from about 106 nm to 11.8 nm. The silicon carbide Fresnel zone plate prepared by this technology exhibits well focusing and imaging properties.

We fabricated blue phosphorescent organic light-emitting devices of A and B groups by using B3PyPPM as electron transport layer and TCTA and mCP as host. The structure are: ITO/HATCN(5 nm)/TAPC(45 nm)/TCTA∶FIrpic(15%,15 nm)/B3PyPPM(X nm)/B3PyPPM∶Cs(15%,10 nm)/Al and ITO/HATCN(5 nm)/TAPC(45 nm)/mCP(5 nm)/mCP∶FIrpic(15%,15 nm)/B3PyPPM(X nm)/B3PyPPM∶Cs(15%,10 nm)/Al. The values of X are 40 nm, 45 nm, 50 nm, and 55 nm, respectively. Experiments show that the devices which use mCP as host is far better than the device using TCTA as host. The maximum luminance of 14 930 cd/m2 and the maximum current efficiency of 9.9 cd/A are obtained. The efficiency roll-off in EQE is only 10.1% when the luminance rises from 500 cd/m2 to 3 000 cd/m2. Since B3PyMPM can improve the injection characteristics of electrons, the turn-on voltage of the two groups devices are 2.3 V and 2.8 V, respectively, which is lower than the Firpic blue phosphorescent OLEDs fabricated with other electron transport layer materials. At the current density of 30 mA/cm2, the spectra of all devices have a major peaks at 474 nm and a vibrational peak at 496 nm. As the thickness of B3PyPPM increases, the intensity of the shoulder increases due to the microcavity effect. The microcavity phenomenon existing in the device is studied in detail by optical simulation.

In order to investigate the characteristics of the back-side surface, i.e., Al/Si, of graphene/Si solar cells, a ultra-thin magnesium oxide interlayer with various thickness between the Al electrode and the silicon substrate was prepared by using a successive thermal evaporation deposition technology. The current-voltage curves, external quantum efficiency, series resistance, and back contact resistance of the graphene/Si solar cells with different thickness of the magnesium oxide interlayer were measured. The results show that the photoelectric conversion efficiency, series resistance and back contact resistance increased first and then decreased with the increase in the magnesium oxide thickness, and the device performance is best when the thickness of magnesium oxide layer is 1 nm. The photoelectric conversion efficiency, series resistance and back contact resistance of the solar cells with 0 nm and 1 nm MgO are 2.90%, 4.2 Ω, 9.6 Ω, and 5.53%, 1.8 Ω, 3.2 Ω.

The electron-optical model of high dynamic range anisotropic focusing streak tube is built. Via calculating the electric field distribution and tracking electron beam trajectory of the whole system, high voltage electrodes which may trigger the electric sparks are analyzed; the effect of electric quadrupole lens on the streak tube magnification, static and dynamic image quality are studied; the temporal distortion is calculated. The results show that the temporal distortion in the 20 mm long slit is only 15 ps, in which the variation of the ramp voltage imposed on the deflectors is as small as 3.06 V. Thus, the slit image distortion caused by the temporal distortion can be ignored. The optimum time resolution of 1.8 ps and dynamic range of 1 000∶1 at temporal resolution of 8 ps are successfully demonstrated in the experiments.

To overcome the limitations of traditional Fourier transform algorithm in spectral restoration, a modern spectral estimation method, multiple signal classification (MUSIC) algorithm, is introduced to recover spatial heterodyne signals based on the characteristics of spatial heterodyne spectroscopy. Criterion Autoregressive Transfer function (CAT) criterion is used to estimate the spatial dimension. The results show that there is a deviation between direct fixed dimension value by CAT criterion and the optimal one, while the direct fixed dimension value minus 3 can be regarded as a new improved criterion for spectral restoration. When applied to the spatial heterodyne interference data, the spectral restoration results of this improved CAT criterion as well as its related MUSIC algorithm is better than those of direct Fourier transform. Spectral Angel Mapper (SAM) and Mean-Squared Error (MSE) are used as the performance evaluation indexes. Compared with the ideal spectrum, SAM of MUSIC algorithm restoration spectra is 0.764 and MSE is 0.040 for potassium bimodal peak signal processing. For the multi-spectrum peak signal processing of Ne lamp, SAM is 0.806 and MSE is 0.046. The results of polychromatic light are 0.988 and 0.089, respectively. Indicating that this adaptively dimensioned MUSIC algorithm with improved CAT criterion has advantages to the spatial heterodyne spectral restoration and improves the power spectrum restoration effect.

A super-sensitive, high-specific immunoassay of tumor marker based on Surface Enhanced Raman Scattering (SERS) was developed with the sandwich-type immune structure consisted of Ag-covered polystyrene sphere (PS@Ag) probes and Ag-deposited Si pyramid array (Si@Ag) substrate. The PS@Ag immune probe was prepared by successively immobilizing 4-Mercaptobenzoic acid (4-MBA) and Anti-AFP antibodies on the surface of in-situ reduced PS@Ag nanoparticles. The Si pyramid array was fabricated using PS spheres as a template, combining with Langmiur-Bloggt method, reactive ion etching and wet chemical etching techniques. Then, Si @Ag immune substrate was prepared by successively depositing Ag film and immobilizing Anti-AFP antibodies on the surface of Si pyramid array. The results demonstrate that the constructed immunoassay platform exhibits high sensitivity with the limit of detection of 1.75 fg·mL－1 and wide linear range from 2 fg·mL－1 to 200 ng·mL－1. In addition, the detections of serum sample show the SERS-based platform is not only well-consistent with that of chemiluminescent immunoassay but also more sensitive, which could be potentially applied in the practical clinical diagnoses of cancer.

An adaptive window width centroid correction algorithm is proposed based on echo signal modeling for lidar distance detection. An adaptive window width model is established to obtain centroids based on the relationship between window width and saturation. The algorithm is adjusted by the median, and achieves high-accuracy time extraction of saturated waveforms. The simulation is carried out through Matlab, and the results show that when the SNR reaches 10 dB, the accuracy of the adaptive window width centroid correction algorithm is 0.3 ns. Compared with traditional waveform centroid algorithms, the accuracy of the proposed algorithm is improved by 92% and the problem of centroid drift can be effectively solved. The algorithm is verified utilizing board-level measured waveforms and is corrected for distortion of the measured waveforms, the results show that the time accuracy of algorithm can reach 0.5 ns , and ranging accuracy can achieve 7.5 cm in case of saturated waveforms. The proposed algorithm can effectively increase the dynamic range of ranging and reduce system complexity.

Using sulfur powder and MoO3 powder as raw materials, the MoS2 film was synthesized by chemical vapor deposition method, and was characterized by optical microscopy, atomic force microscopy, raman spectroscopy and X-ray diffraction. Results show that the crystal morphology of the MoS2 is triangle with size of 60 μm and thickness of 0.7 nm; and as one kind of the ideal substrates for surface-enhanced Raman scattering, two-dimensional MoS2 can promote the charge transfer between the organic molecule and MoS2, so the Raman intensity of them are enhanced. The pentacene was adsorbed onto the MoS2 film by physical vapor deposition method, and the organic-inorganic pentacene/MoS2 heterojunction with ideal rectifier characteristic was prepared. Analysing the ln(I/V2)-1/V curve, it is seen that the Fowler-Nordheim tunnelling phenomenon occured through the heterojunction; logI-logV curve shows that charges transport controled by ohmic conduction at 0~1 V voltages zone, and space-charge-limited currents predominate at over 1 V voltages zone. The research of MoS2 single-layer film and pentacene film will be contributed to the optoelectronic field.

To investigate the phase transformation characteristics of vanadium dioxide thin film irradiated by infrared laser, the experiment was carried out based on pump probe method. First, three groups of VO2 monocrystalline epitaxial thin films with thickness of 20 nm, 40 nm and 60 nm were prepared by oxy-molecular beam epitaxy, moreover, the CO2 continuous laser with 10.6 μm was used as the pump beam, nanosecond pulse laser with 1 064 nm and 3 459 nm wavelength were used as probe light respectively, and the three groups of films were irradiated respectively. It was found that the mean values of transmittance reduction of 1 064 nm probe laser after phase transformation of the three groups of films were 5.26%, 6.2% and 8.92%, respectively, and the reflectivity reduction was 3.09%, 6.56% and 4.93%, respectively; for the 3 459 nm probe laser, the mean values of transmittance reduction were 28.4%, 47.78%, 55.13%, and reflectance increase were 6.65%, 17.87% and 7.49% respectively. The results show that the incident laser before and after the phase transformation of VO2 thin films prepared by molecular beam epitaxy were both mirror reflected; the phase transition properties of 1 064 nm probe were not as significant as that of 3 459 nm probe; the increase of film thickness will reduce the transmittance before the phase change, while the decrease after the phase change is more obvious; before and after the phase transition, the film keeps almost opaque to CO2 laser. The investigation will provide a reference for the application of film.

Silica films were deposited on a silicon substrate by a plasma enhanced chemical vapor deposition method to study the stress variation and the refractive index distribution at different process conditions. The stress tester was used to measure the deformation of the wafer before and after coating, allowing the calculation of the film stress, and the prism coupler was used to measure the refractive index distribution. Under the same condition, when the flow ratio of SiH4 to N2O is set to 24, 27.6 and 30, the average refractive index of the film are 1.466 7, 1.459 2 and 1.455 7, respectively, at the wavelength of 1 539 nm, and the correspoonding compressive stress of the film are -50 MPa, -200 MPa, and -430 MPa, respectively. When the flow ratio of SiH4 to N2O is set to 22.6, 24, and 27.6 after minxing 8.3×10-7 m3/s GeH4, the average refractive indices are 1.4758, 1.4714 and 1.4633, respectively, and the corresponding wafer stresses are 25 MPa, -210 MPa and -270 MPa, respectively, which is a changing process from the tensile stress to the compressive stress. The result show that at the same flow ratio of SiH4 to N2O, GeH4 diffusion increases the refractive index and the compressive stress of the film. It turns out that with the reasonable selection of the process conditions, a refractive index stabilized silicon oxide waveguide film can be prepared, thereby improving the yield of the device over the entire wafer.