Highly attenuated laser pulses based on Gaussian beams are used as single-photon sources. It is assumed that this laser beam has an initial Gaussian temporal pulse shape and a TEM01 mode Laguerre-Gaussian spatial profile. Based on the Rytov approximation and the modified von Karman spectrum model of refractive-index fluctuations, the influence of atmospheric turbulence on a single-photon acquisition probability in satellite-ground quantum communications was studied. Theoretical models of the single-photon acquisition probability in an uplink channel and a downlink channel were established. The single-photon acquisition probability was analyzed for laser links between a ground station and a satellite in a low earth orbit. The results show that, the single-photon acquisition probability in the uplink channel depends strongly on the refractive-index structure parameter at the ground C2n(0) and decreases as C2n(0) increasing. However, in the downlink channel the single-photon acquisition probability does not depend on C2n(0), that is, atmospheric turbulence has little influence on it.

Propagation properties of partially coherent Gaussian-Schell model beam, under the condition of considering the atmospheric turbulence of inner-scale and outer-scale, were studied in the atmospheric turbulence. Using the model of modified Von- Karmon spectrum which considers its inner-scale and outer-scale, the expressions of intensity distribution, wander variance and beam width of partially coherent beam were deduced in the atmospheric turbulence. The influence to partially coherent beam, on the turbulence along a slant path and a horizontal path considering the inner and outer scale, were analyzed in different turbulence intensity. The results show that, under the same condition, the anti-turbulence ability of the beam propagated in the atmosphere along a slant path is more better than the horizontal path. In addition, compared with the inner scale of the atmospheric turbulence, the outer-scales of the beam propagated in the atmosphere has a greater effect on the wander variance, the outer-scales have a minor effect on the intensity distribution and beam width, when the outer-scale increasing, wander variance is more serious. Furthermore, compared with the outer scale of the atmospheric turbulence, the inner-scales has more effect on intensity distribution and beam width. When the Inner-scales reduced, the beam expanding phenomenon is becoming more and more serious. Intensity distribution is more scattered, and inner-scales of wander variance almost has no effect.

Based on Andrews and Philips classical wander variance model, combining with the cross spectral density function of partially coherent light Airy and Tatarskii power spectrum, the coherent analytical formulas of expansion and wander of Airy beam in atmosphere transmission were deduced. The influence of the parameters such as the different truncation, the turbulence intensity and the coherence on the expansion and wander of Airy beam was analyzed. Then the results were compared with the results of Gaussian beam. The study has shown that, the different truncation, turbulence intensity and coherence have the bigger influence on beam wander, the more their value is, the more serious the wander will be. The inner scale has so little effect on the beam wander that can be ignored. Under the same conditions, Airy beam wander is two orders of magnitude smaller than that of the Gaussian beam, and itself has self recovery characteristic and strong inhibition of turbulence characteristic.

A method to measure modulation property of liquid crystal based on diffraction grating was proposed. This method utilizes liquid-crystal to establish the binary phase gratings with the phase of 0 and φ respectively, the relation between intensity of zero-order diffraction spots and φ can be deduced by Fourier transformation, and the relation between intensity of zero-order diffraction spots and voltage of liquid crystal pole was measured by experiment. Therefore,relation between phase φ and voltage of pole liquid crystal can be achieved, that is the modulation property of this liquid crystal. Finally, the modulation property was used to creat liquid crystal phased array to steer laser beam, experimental results indicate that phase error is less than 1×10-3 rad.

According to the generation mechanism of speckle, utilizing the concept of interference on a pixel point, a speckle suppression method was proposed which can reduce the Speckle Contrast (SC) of the projection image by limiting the phase distribution range in the optical field. The SC formula is derived in the uniform interval phase range for partially developed speckle conditions, showing that when phase distribution rang is limited between 0.6π and 2π, a quasi-oscillatory behavior of SC appears with the change of phase distribution rang; and SC will be falling rapidly with the lessening of phase distribution rang when phase distribution rang is smaller than 0.6π. An ideal simulation model and a real simulation model were established to verify the correctness and feasibility of this method. In the ideal simulation model, the SC can be reduced from 66.44% to 0% as the phase range limitation varying from 2π to 0. In the real simulation model, the actual structure of the optical path was simulated in the laser projection system, there are two diffractive optical elements in the real simulation model, one is for laser shaping, and the other one is for limiting the phase range of optical field, the SC is reduced from 92.78% down to 2.09% in the real simulation model. The proposed approach presents a significant reference with a low power consumption and a stable display architecture for speckle suppression application in holographic display.

Aiming at the projector distortion and the change of fringe periods and fringe series, a calibration method of single period fringe and double four-step phase-shifting algorithm was proposed. Designing and generating two groups of horizontal and vertical single period grating fringe images respectively, the camera captures the single period grating fringe images which projected onto the calibration plate with circular logo at the same time, and superposes the two phase master maps which obtained by double four-step phase shift and unwrapping the phase master map. Then the pixel coordinate of projector is calculated by the unwrapping absolute phase. Finally, the projector calibration is converted into a mature camera calibration. Experimental results indicate that the maximum re-projection error and the root mean square error of the projector calibration precision of simulation experiment are about 0.4 pixel and 0.132 96 pixel respectively. The maximum re-projection error and the root mean square error of the projector calibration precision of simulation experiment are about 0.46 pixel and 0.143 12 pixel respectively. Compared with the existing projector calibration methods of projecting fringes by tri-frequency phase unwrapping, 8 grating images can be reduced by the proposed method. The shortcomings of projector calibration method by projecting grating fringes and the calibration accuracy and the calibration efficiency can be improved.

An optimizing method for the core arrangemnt of three-mode twelve-core fiber was proposed. After investigating the characteristics such as inter-core crosstalk, threshold value of bending radius and Relative Core Multiplicity Factor (RCMF), the optimized scheme for One-Ring Structure (ORS) and Square-Lattice Structure (SLS) were presented. For ORS, it is hard to find an appropriate core deployment to meet both requirements that crosstalk is not higher than -30 dB/100 km at the wavelength of 1 625 nm and the cable cutoff wavelength is not larger than 1 530 nm. For SLS, crosstalk can be lower than -30 dB/100 km after bending radius being larger than the threshold value, maximum cutoff wavelength is not larger than 1530 nm and RCMF can reach ~15 at the wavelength of 1625 nm, which indicates that SLS is a more suitable core arrangement than ORS for the three-mode twelve-core fiber.

An all-fiber sensing system based on the Mach-Zehnder Interferometer (MZI) and Fiber Bragg Grating (FBG) was proposed for the measurement of transverse pressure and temperature simultaneously. The MZI was fabricated by splicing of a lateral-offset Multi-Core Fiber (MCF) with two single mode fibers, the modal interference was formed due to the mode field mismatch among MCF and Single Mode Fibers (SMFs), which made the external pressure directly acted on the light field inside of the multi-core fiber, thus a high pressure sensitivity of interferometer can be achieved. Experimental results show that the pressure sensitivity of the MZI is 28.57 nm/(N·mm-1), and the linearity is 0.997, while FBG is not sensitive to the pressure change. Both the MZI and the FBG show a good linearity between the wavelength shift and temperature, and the sensitivity is 56.1pm/℃ and 11.3pm/℃, respectively. For a spectrometer with a resolution of 0.02 nm, the proposed sensor can reach a resolution of 7.0×10-4N/mm for pressure and of 0.03℃ for temperature. The transmission spectrum of the MZI and the resonance peaks of the FBG have different spectral responses to pressure and temperature changes. By using optical spectrum analyzer to monitor the wavelength shift of the transmission spectrum of the sensor, so that the dual-parameters of pressure and temperature can be measured conveniently.The proposed sensor has a simple structure a high sensitivity, it can be well applied to transverse pressure measurement.

To fabricate the Sagnac interferometer sensor, a polarization-maintaining fiber with the length of 8 cm was spliced between two single-mode fibers, and the polydimethylsiloxane material was coated on the polarization-maintaining fiber, then the polydimethylsiloxane functionalized polarization-maintaining fiber was integrated into a fiber coupler to form a Sagnac loop. When the polydimethylsiloxane absorbs volatile organic compounds, the polydimethylsiloxane will be swelled and the wavelength of interference peak will shift, so that the concentration of volatile organic compounds can be measured by monitoring wavelength shift. The response of the sensor to the concentration of volatile organic compounds was measured experimentally, and the results show that the sensitivity of the sensor is 1.03 pm/ppm when the concentration ranges from 0 ppm to 6 000 ppm. The optical spectrum analyzer with a 0.02 nm measurement precision was used in experiments, so the precision could reach about 19.4 nm in the concentration range from 0 to 6 000 ppm. The sensor′s sensitivity improves 4 300 times which compared to grating fiber with polydimethylsiloxane material sensor.

Based on the fundamental principle of phase diversity technique, a prototype space-borne camera was used to experimentally demonstrate the effects of wavefront reversal of phase diversity technique through laboratory and outfield push-broom imaging experiments. Experimental results demonstrate that, the accuracy of wavefront reversal based on phase diversity technique is near 1/40λ(λ=632.8 nm)by using the root-mean-squares of residual wave-front errors between the really obtained wave-front through Zygo and the calculated wave-front through phase diversity as a criterion. At the same time, by carrying out deconvolution to the degraded push-broom images using the estimated wave-front, the image quality could be prominently improved. The signal-to-noise ratio could be improved at least 40% and the modulation transfer function at Nyquist frequency could be improved 80% above, which indirectly proves the effectiveness of phase diversity technique as well. The work reported in this manuscript will pave the way for in-orbit application of phase diversity based wave-front sensing technique in future.

The dynamic clamping method of space remote sensing cameras was proposed to solve the above-mentioned problem. The method can realize adequately quantization of scene information by subtracting the value of atmospheric path radiation at the analog front end of camera. Imaging chain model for space remote sensing cameras was established first, and the effect of atmospheric path radiation on the image grey-scale area was analysed. Then, the dynamic clamping camera was developed, therefore the analog signal subtracted from the camera hardware circuit was implemented. Besides, experiments were carried out to test the dynamic clamp camera. And the value of atmospheric path radiation calculated by MODTRAN software was converted to value of camera clamp in experiments. Experiments results showed that, the low end information of camera can be fully used by this method, and the image grey-scale range increases by 62 percent. Thus low end quantitative information can also be adopted by designing dynamic clamping for space remote sensing cameras. Then the information of targets can be represented by more quantization bits, and the radiometric resolution is improved as well as more details information of image are remained.

An optical sensor based on symmetrical metal cladding optical waveguide was proposed. Utilizing the ultra high order guided modes motivated by this sensor which are ultra sensitive to the imaginary part of the refractive index of the guide wave layer as probe, and combining with the specific color rendering principle of diphenylcarbazide and hexavalent chromium ion, the trace amounts of hexavalent chromium ion in water were detected. The theoretical and experimental results show that, the limit of detection is 1ug/L which is same as the international standard. This new method has a lot of advantages, such as lower specimen, shorter time, good real-time, high stabilization, lower cost and so on.

Aiming at this threshold selection problem for multi-current projection fusion, a method based on dynamic time warping was proposed. Firstly, the sequences of gray value-effective edge gradient is calculated from the projections with different currents. Secondly the dynamic time warping distance is used to match the similarity of the above sequences, and the optimal fusion threshold is automatically determined. Finally the sub regions are extracted for fusion based on the threshold, achieving a higher dynamic range of the detector. The average error of fusion threshold at each angle is only 2.26% calculated by the proposed method, which could avoid subjectivity in the fusion threshold selection. Simulation and experimental results show that both the SNR and the measurement accuracy of geometric dimensions based on the fused computed tomography image are better than those with a fixed threshold.

In order to measure both large and small particles, based on the analysis of the pulse signal of the spherical particle irradiated by a thin beam, a method for extracting the equivalent particle size information was proposed. This method combines the amplitude and duration of the pulse signal by the integral of the pulse signal, which makes the equivalent particle size information extracted from the pulse signal more accurate. The ideal pulse signal was simulated and experiment was made by using standard polystyrene latex particles. The results show that the method can effectively extract the particle size information of large and small particles, which broaden the detection range. In addition, the effect of flow velocity and noise on the extraction of the particle size was analyzed. When the flow rate is less than 10%, the measurement error is less than 5.4%, and when the noise is less than 1%, the measurement error is less than 0.5%.

A method for measuring the étendue of LED was proposed based on the near-field model of the LED source. The curve of luminous power on étendue can be obtained by tracing rays data in LED near-field moled, which can directly reflect the étendue characteristics and the energy efficieny of LED source. Taking the UV-LED array surface source in the exposure system as an example, the actual measurement of the three different models of UV-LED were carried out. The designer can make a judgment on the UV-LED beam quality by the étendue and energy efficiency curve, which can provide help for the optimization design of the UV-LED array surface source.

Combing the structure dynamic design method with the control theory, the flexible electromechanical coupling control model was built which is difference from the traditional rigid control model. The relationship between the structural fundamental frequency and servo bandwidth was analyzed, then the dynamic quantitative design principles were put-forward, The experiment results show that, the theodolite structure frequency should be far away from the resonant frequency of the system, and meet ωn≥3ωr at least, which is effective and feasible, has solved the high precision large theodolite electromechanical resonance problem, and provide the basis of engineering for designing fast response and high tracking precision of photoelectric theodolite.

The excipients contents in the Amlodipine Besylate Tablet were rapidly detected combing of the near infrared spectroscopy and Chemometrics. Characteristic wavelength variation points were screened by methods of Random Frog, Variable Importance Projection and Competition Self-Adaptive Reweighted Sampling. After processing the original spectrum by 9 kinds of spectrum pre-processing methods, the Partial Least Squares (PLS) model and Support Vector Regression analysis (SVR) model were established respectively and compared to each other. And then the optimized model was applied to test the samples. The results show that the effect of Random Frog is better for the selection of optimal characteristic wavelength variables in the samples involved; For the model predictions, the effect of PLS quantitative model is better for the evaluation parameters in the determination coefficient and RMSEP of the five indexes, when compared with that of the SVR model, and the Relative Percent Difference (RPD) values are all more than 3.0. The standard error of the tested values and measured values for samples are both less than 1.30; Paired t-test shows that there is no significant difference at the significance level of a=0.05. So near infrared diffuse reflectance spectroscopy can be used to rapidly detect the excipients′ contents in the Amlodipine Besylate Tablets, with a good repeatability, an intermediate precision, a linearity, accuracy, can provide a good reference for the rapid detection of other pharmaceutical excipients′contents.

An orange-red laser was designed and developed based on a composite cavity structure with tunable wavelength, W-level continuous output. It consisted of a resonant cavity which generated p-polarized 1 062.9 nm fundamental frequency light based on laser diode side pumped Nd∶GdVO4 crystal and a single resonant optical parametric oscillator using a periodically poled crystal MgO∶PPLN with three-poling periods (29.0 μm, 29.8 μm, and 30.8 μm). In the overlap region of the two resonant cavities, the type-II critical phase-matched crystal KTP was used to bring about inner-cavity sum-frequency generation with the s-polarized signal light and the p-polarized 1 062.9 nm fundamental frequency light. By the tuning of three different polarizations of MgO∶PPLN crystal and the temperature tuning in the range of 30℃~200℃, the wavelength tunable orange-red laser with W-level continuous outputs in three bands(613.4~619.2 nm at 29.0 μm, 620.2~628.9 nm at 29.8 μm and 634.4~649.1 nm at 30.8 μm) were obtained. In addition, the wavelength tunable mid-infrared idlers were gained in the corresponding bands(3 980.0~3 758.5 nm at 29.0 μm, 3 714.2~3 438.3 nm at 29.8 μm and 3 278.0~2 940.2 nm at 30.8 μm). By changing the poling periods at 30℃ minimum temperature, the maximum continuous output powers were measured as 1.52 W (at 613.4 nm), 2.21 W (at 620.2 nm) and 3.03 W (at 634.4 nm). At the same time, the maximum continuous output powers of the three corresponding idlers were measured as 2.36 W(at 3 980.0 nm), 3.17 W(at 3 714.2 nm) and 4.13 W(at 3 278.0 nm), respectively.

An all-normal-dispersion mode-locked Yb-doped fiber laser with wide spectrum was investigated. The stable mode-locking is realized based on the nonlinear polarization evolution. At the pumping power of 500 mW, the power of mode-locked laser can produce more than 130 mW output at the repetition rate of 28.1 MHz with pulse duration of 3.8 ps. In order to explore the spectral characteristics of all-normal-dispersion laser, the cavity is implemented by splicing the 50-m single mode fiber and by removing the birefringent filter. Under the pump power of 500 mW, the stable dissipative solitons are obtained with 90 mW output power, 3.58 MHz repetition rate, 519 ps pulse duration and spectrum ranging from 1 005~1 140 nm.

Pulse laser fuze of conventional ammunition cannot accurately obtain the azimuth information of target. Therefore, the circumferential azimuth detection scheme of single beam laser fuze was designed based on magnetic-electric detection. The magnetic-electric detection system was modeled; a cylindrical permanent magnet rotating magnetic field model was established. The analytic expression of magnetic position which is measured by magneto resistive sensor was deduced. According to the analytical expression of the magnetic signal, rising along the cycle threshold detection method was put forward. The high precision azimuth resolution was achieved by using the method of combining FPGA with TDC-GP21 to measure high precision time, which is the time of laser echo signal appearance and the period of motor speed signal. According to the scheme, prototype was designed, and the program of the host computer was finished. The experiment of azimuth angle detection was carried out. The experimental results show that, the magnetic-electric detection system uses multiple shield method which can effectively suppress electromagnetic interference. Meanwhile, this system can achieve real time monitoring of the motor speed and range angle solver. Azimuth solution calculation error is in plus or minus 2°. The magnetic-electric detection system can meet the requirement of high precision and anti-interference ability of the azimuth angle measurement of laser fuze.

A structure of two-dimensional incident left-handed metamaterial composed of double trapezoid metal strips was proposed based on paralleled metal strips and thin metal wire. The structure consists of dielectric-slab and anti-symmetrical trapezoid metal strips on each side. Compared with the traditional left-handed metamaterial structures, this structure not only has double left-handed frequency band under the parallel incidence of electromagnetic wave, but also has a good expansibility, and it is easy to produce. By using the simulation software, the structure is analyzed respectively when electromagnetic waves are incident perpendicularly and when they are parallel to the substrate. Results show that, the structure can show double negative properties either under the incidence of electromagnetic waves paralleled or perpendicular. Besides, with the upper base size of the structure being greater for each 0.5 mm, the frequency band of double negative properties moves to higher frequency band about 0.2 GHz and 0.4 GHz.These can be as reference values in the research of left-handed metamaterial based on paralleled meta strips.

Using by the method of one step Ag and Cu dual elements based Metal Assisted Chemical Etching(MACE), a nano-light trapping structure was prepared at a room temperature on the surface of the multicrystalline silicon. Then, the silicon wafers were made an anisotropic refactoring using by a Nano Structure Rebuilding (NSR) solution at a temperature of 50℃, so that the invert pyramid light trapping structures with different sizes were prepared. The reflectance and surface morphologies of multicrystalline silicon, and the minority carrier lifetime of the passivated multicrystalline silicon were measured by spectrophotometer, scanning electron microscopy and Sinton WCT-120 tool respectively. The results show that, the main factor to affect the final size of invert pyramid structure is the depth of the as-etched nanostructure. The deeper the depth is, the larger the final size of invert pyramid structure becomes. With the increase of NSR refactoring time, the size of the invert pyramid structure goes larger and the reflectance becomes higher too. While the minority carrier lifetime increases with the increasing of the size of invert pyramids after atomic layer deposition passivating, one should make a balance between anti-reflection result and passivation effect. An invert pyramid with an edge length of 600 nm is found to be an optimal size, corresponding a reflectance of 9.87% and a minority carrier lifetime of 37.82 μs.

Based on the bidirectional reflectance model, the polarization characteristics and spectral radiosities of four space target samples, such as carbon fiber, carburizing film, F46 and OSR, were measured. By calculating the Stokes parameters of the samples, the degrees of linear polarization and polarization orientations under multiple observing angles were obtained and recorded. The statistical results show that, the different samples have great differences in average and variance of the degree of linear polarization and Orientation. The analysis of the difference between the average and variance of samples can improve the effects in detecting and identifying simples efficiently and solve the “Same object with different spectrums” and “Foreign body in the same spectrum” problems occurred in spectroscopic techniques. The polarization property provides more optical information for remote sensing, which is an effective and reliable method for target recognition.

Based on the biased one-photon photorefractive crystals, the solutions of incoherently coupled bright and dark soliton families governed simultaneously by linear and quadratic electro-optic effects were derived theoretically. The intensity profile and stability of soliton families were investigated. The different functions of the linear and quadratic electro-optic effects were discussed and the results show that, the interplay between the linear and quadratic electro-optic effects can enhance the photorefractive nonlinearity for bright soliton families but weaken the photorefractive nonlinearity for dark soliton families. Moreover, the bright soliton components can remain invariant during propagation process, and the dark soliton components show instability for long propagation distance.

The intensity of a fixed point in the interference fringes is closely related to the phase change of interference fringes. According to this principle, a real-time phase locking system was established by the analysis of the intensity field. The intensity voltage of a fixed point in the interference fringes was detected as a feedback signal by a photodetector, and an acoustic optical modulator was used to shift the frenquency of the Gaussian beam in real time. By setting intensity voltage to a fixed value, phase locking function was realized. Theoretical model of fringe phase locking system was derivated and verified by experiment. A phase locking controller was also designed based on the model. The experiment results illustrate that, the phase drift is within ±0.04 period under the 400 Hz control frequency, which satisfies the exposure requirements of interference lithography.

An injection-phase locked optoelectronic oscillator based on injection locking and phase-locked loop techniques was proposed. Utilizing the injection locking to reduce the close-in phase noise and increase the side-mode suppression ratio. Using the phase-locked loop to improve the frequency stability of the optoelectronic oscillator by detecting the phase between the output signal of the optoelectronic oscillator and the external injection source and also to furtherly improve the close-in phase noise performance. The experimental results show that, when the electrical filter′s center frequency and 3 dB bandwidth are 9.5 GHz and 20 MHz, single mode oscillation at 9.5 GHz is realized by a 6 km-fiber single loop injection-phase locked optoelectronic oscillator. When the injection locking bandwidth is 1.98 kHz, the phase noises of the optoelectronic oscillator′s output signal are about -125 dBc/Hz at 1kHz offset frequency and -147 dBc/Hz at 10kHz offset frequency, the SMSR is higher than 70 dB, and the Allan deviations are about 1.37×10-11@1s and 1.22×10-11@1000s.

Based on the Micro Electronic Mechanical System(MEMS) processing, a large size 2-D scanning mirror driven by electromagnetic force was designed and implemented. Two different driving methods were compared, and the method of dipole driving was chosen because of its higher torque. Meanwhile, the static response and dynamic response of the device were analyzed by using finite element simulation, the simulation results matched with the measurement data of the device. The fabrication and packaging steps for the MEMS mirror were described in details, and the mirror was fabricated. The testing results show that when the driving current reaches 120 mA, the MEMS mirror has static titling angles of ±4.5° and ±5° along slow axis and fast axis respectively. The scanning resonant frequency for the mirror along slow axis is 348 Hz, and 660 Hz along fast axis. Finally, the MEMS mirror was used in laser display system to reduce the laser speckle, the speckle contrast can be reduced to 4.2%, and the image quality of a laser display system can be greatly improved with the MEMS mirror.