With a movable quadrupole magnetic trap (QMT) generated by two pairs of partly-overlapped magneto-optical trap (MOT) and transfer coils, a highly efficient transport of cold 87Rb atoms to the atom chip surface is realized. By the QMT movable means of linearly increasing the current in the transfer coils but simultaneously keeping the current in the MOT coils constant, the velocity profile of the moving trap is Blackman-type-like. With this QMT movable scheme, the cold atoms are transferred to the atom chip surface from the MOT center. In the transfer process, the cold atom temperature is increased by about 30 μK, and the transfer efficiency is above 90%. This system provides an appropriate cold atoms source for the atom chip interferometer and also can be used to investigate the interaction between atom and chip surface.

A purple fringing correction method for large-area purple fringing is proposed based on color information. Considering the causes of purple fringing, the existing method for purple fringing detection is improved by making use of the chromatic aberration theory. When correcting the purple fringing, the proposed classification correction method and the method of avoiding error correction measures are proposed based on object color information, while a method for remaining purple fringing removal is corrected, so as to correct the purple fringing and reduce the error correction at the same time. Experimental results indicate that the proposed method can obtain better correction effect than the existing methods for large-area purple fringing in various scenarios of images. The corrected images are improved significantly in the subjective visual and objective data in the evaluating indicator.

Stochastic parallel gradient descent algorithm (SPGD), a phase control method based on directly optimizing performance index, has good applicability in adaptive optics. The algorithm involves two variable parameters: gain coefficient and random perturbation amplitude, whose values have great influence on the convergence of the algorithm. The requirements of the parameter values for the convergence of SPGD algorithm are discussed, and the value range of parameters are analyzed by combining with the principle of the algorithm. Furthermore, a large number of simulations are conducted to analyze all the gain coefficients and the amplitude of random disturbance, which can ensure the convergency of bilateral SPGD. Meanwhile, the lower limit of the random disturbance amplitude is obtained, and the reason for its existence and the lower limit value are also analyzed theoretically and experimentally. With the existence of phase noise in coherent combination, the range of parameters for the algorithm to be convergent is analyzed with different phase corrector parameters.

Both theoretical analysis and numerical simulation for displacement Talbot lithography are conducted based on angular spectrum diffraction. The factors which influence the grating fringe quality obtained by displacement Talbot lithography such as displacement distance, starting position, non-uniform displacement velocity and different characteristics of lighting source are also discussed in detail. Simulation results show that, when the displacement distance is integer multiples of Talbot period, the factors of initial position and non-uniform displacement velocity have little influence on imaging quality of displacement Talbot lithography. When there is a certain spectral width of the incident light source or the divergence angle is not larger than 0.05°, the displacement Talbot lithography can still obtain double frequency grating fringes whose contrast is more consistent, which verifies that the displacement Talbot lithography possesses an outstanding process applicability. Displacement Talbot lithography does not require expensive and complicated projection optical system, and can overcome the problem of limited depth of focus for Talbot self-imaging. Meanwhile, displacement Talbot lithography has higher tolerance for the positioning accuracy between mask and substrate as well as the substrate planeness. The method has promising potential to be applied in non-planar substrate for the manufacture of periodical micro structures with wide area, low expense and high precision.

For the random fluctuation of nonlinearity curve of fiber Fabry-Perot tunable filter (FFP-TF) increasing in temperature changing environment, which results in the instability of fiber Bragg grating (FBG) demodulation system, a novel method based on auxiliary optical fiber Michelson interferometer (AFMI) to stabilize demodulation performance is proposed. The optical frequency subdivision in wavelength interval of Fabry-Perot etalon is achieved, and the demodulation algorithm by local optical frequency subdivision is compiled. Under temperature changing environment, we investigate amplitude of fluctuation by an AFMI, whose spectral interval is 9.53 GHz. The experiment shows that the amplitude of fluctuation is ±28.5 pm without AFMI, and standard deviation is 8.6 pm. However, the amplitude of fluctuation is ±3.5 pm with AFMI, and standard deviation is 1.4 pm. The wavelength demodulation stability of fiber Bragg grating in temperature-variable situation is effectively improved.

The communication ability of the laser communication networking antenna is determined by its transmitting and receiving efficiency. A new type of networking model of antenna system is proposed, and the algorithm of transmitting and receiving energy efficiency is analyzed through mathematical model. Based on this model, the equation of transmitting and receiving energy efficiency is derived. After that, the accurate functional relationships between the energy transmitting and receiving efficiency with optical structure parameters such as opening up and down diameters, focal length of rotating paraboloid, unit aperture and focal length of converging lens are discussed. These conclusions can be applied to the structure design and optimization of laser optical communication networking antenna. Finally, under the background of three (low earth orbit) LEO satellites within 1000 kilometers of networking communication system and the velocity up to 2.5 Gb/s, the minimum laser power that satisfies the communication situation, the curves reflecting the changes of transmitting efficiency with tracking communication angle, and the receiving efficiency of the networking antenna system are calculated and analyzed.

A novel overlapping code system is proposed to enhance the communication performance of double-layer overlay coding visible light communication system. With full consideration of the characteristics of far and near distance communication, the proposed system makes a creative combination of trace orthogonal coding and overlapping systems. This combination ensures the trace orthogonal property of two layers signals and therefore eliminates the interlayer interference. Moreover, an enhanced Euclidean distance and coding gain can be obtained to extract better performance. For this system, the same decoding performance can be obtained with the sum detection algorithm of linear complexity as well as with maximum-likelihood (ML) detection. The effect of different power allocations on system performance is analyzed by deriving the closed expression of bit error rate based on ML, and three constellation designs are then presented. Simulation results show that compared with existing double-layer overlapping systems, the new system based on layered trace-orthogonal coding can effectively improve communication performance.

The mode conversion technology is one of the key technologies of the mode division multiplexing, which can realize the transformation between arbitrary optical modes. Moreover, it is the basis for the realization of channel access, switching and multiplexing. A spatial light modulator is used to achieve different mode distributions. The algorithm to generating phase hologram for mode conversion is improved based on spatial light modulator. By using the adaptive simulated annealing algorithm with graphics processing unit parallel computing, a more than seven fold increase in the computational efficiency of the simulated anealing algorithm is obtained. Finally, a mode conversion platform is established, and the experiment is carried out to prove the effectiveness of the proposed method.

Routing, core selection and spectrum assignment in multi-core elastic optical networks are studied. A global constrained optimization model is established, and a heuristic algorithm and its improved algorithm based on core rotation selection are proposed. In the improved alginthm, connection requests are classified according to different sorting strategies. Connection requests are classified into different groups according to source node, destination node and the selected routing, the selection mechanism based on core rotation in the same connection request group is employed, and the first-fit method is used in spectrum assignment for the selected core. Simulations are conducted in two networks, and the results indicate that the proposed algorithm and its improved algorithm can obtain better scheme of routing and core selection than the compared algorithms.

In order to test the performance of acquisition and tracking in space laser communications, a satellite vibration analog source system is proposed and designed. The system gets standard vibration power spectral density function by upper computer with LabVIEW software, and then transmits the simulated signals of vibration platform to control system with the core of STM32F4 in order to make the galvanometer swing for pitch and azimuth. Based on SILEX platform model designed by European Space Agency (ESA), the feasibility of the program is derived and verified. Also an experimental site is built to monitor the miss distance in real time by detectors and analysis the miss distance power spectrum. Simultaneously, the pseudo-random sequence in practical applications is processed and optimized. The experimental results show the amplitude accuracy of vibration source is better than 2 μrad and the system simulated results are real and effective. In addition, the amplitude of analog system can reach ±10 mrad since its frequency can be adjusted. Therefore the system can easily simulate different standard models and provide the conditions for acquisition, pointing and tracking (APT) verification in the laboratory.

The autofocus of the scenes containing high bright areas such as light sources is common and the high brightness areas lead to saturation of the image pixels. However, the existing evaluation functions are put forward for normal scenario and these cannot be applied for the scenes with light sources such as the nightscop. A sharpness evaluation function is proposed to remove saturate pixels by analyzing the performance of scenes including light sources in the process of defocus and it can be used to evaluate the image quality of scenes containing light sources or high bright areas. A binary map of focusing window is acquired by modifying the Ostu algorithm, and an expansion region of high bright areas is obtained by morphological expansion method to prevent the dispersion of bright areas caused by defocus blur. The removed bright areas template is put on the gradient information matrix, and the average gradient is used as sharpness evaluation value index. The sharpness evaluation index is tested using multiple sets of focal sequence diagram. The results demonstrate that the proposed autofocus evaluation function is applicable to the scenes containing light sources or high bright areas compared with other four common evaluation functions. The proposed method has favorable unbiasedness, unimodality, stability and broad coverage.

Bioluminescence tomography (BLT) aims to reconstruct the internal bioluminescent source distribution with known optical properties and the measurements of light intensity on the surface of biological tissues. Due to the complexity of near-infrared photons transportation in biological tissues and the limited boundary measurements, the source reconstruction of BLT is a challenging problem. To obtain stable reconstruction with a small amount of measurements, we present a single-view based reconstruction method for multispectral BLT. In this method, we combine an iteratively shrinking permissible region strategy with sparsity-inducing regularization technique to deal with the high ill-posedness of BLT inverse problem. Simulations based on homogeneous numerical phantom are designed to systematically assess the performance of the proposed method in terms of localization accuracy and the ability to resolve two neighboring targets. We investigate single spherical sources with 3 sizes at 4 different depths, and double sources with 3 source separation distances varying from 3 to 9 mm. Simulation results show that based on single view measurement the proposed reconstruction method can yield stable reconstruction with an average 0.5 mm accuracy in single source cases and resolve two neighboring sources with 3 mm separation distance.

The depth measuring range is limited by conventional shadow moiré profilometry. In order to solve the problem, a new method of shadow moiré profilometry, which can increase the depth measuring range, is proposed according to the fringe contrast characteristic of shadow moiré. When the grating is placed at different depths, moiré fringes will be formed on the surface. The shadow moiré profilometry with large depth measurement range is realized by merging the fringe phase measurement results of different depth ranges. The phase distributions of moiré fringes at different depths are analyzed. Methods for phase merging and error compensation are proposed based on the overlapping region. The feasibility and veracity of the proposed method are verified by experiments.

The factors impacting strain precision in the digital image correlation (DIC) method is derived theoretically. It is pointed out that the precision of strain calculation will decrease as the calculation window gets small. In order to improve the effective image resolution, a novel perspective to two-dimensional multi-camera full-field DIC method is proposed for slender specimen. The sub-pixel position of matching feature point pairs is found based on feature point detection and matching algorithm. The matching feature point pairs are registered with high precision using the DIC method. Finally, a gradually optimized homography solution method is developed to solve the image transformation to get the seamless stitched images before and after deformation. Two sets of experiments including pure translation and three-point bending of rubber beam are conducted. In the pure translation experiments, the mean error and root-mean-square error of calculated strain are within 50 με, which verifies the validity of this method. Two-dimensional and three-dimensional multi-camera DIC methods are compared through the three-point bending experiments. Based on the results, merits and demerits of the proposed method are discussed.

An improved nonlinearity correction algorithm by hardware-based equispaced-phase resampling for frequency modulated continuous wave (FMCW) ranging system was proposed. After improvement, equispaced-phase resampling method could be realized in one step by hardware data acquisition. No subsequent complex data processing is needed any more, which will save much memory space and data processing time. Moreover, compared with software-based equispaced-phase resampling method, the improved method had higher sampling accuracy. The effect of nonlinear frequency modulation on ranging precision of FMCW ranging system and the principle of equispaced-phase resampling for nonlinearity correction were explored. On this basis, a new spectral analysis method was presented for the reason that the equispaced-phase resampled data was not equally spaced in time domain and the traditional spectral analysis method is no longer applicable. The computational formulas of peak spectral frequency and object distance were deduced. Their correctness was verified by simulation. Experimental results show that equispaced-phase resampling based on hardware has higher ranging precision and resolution than equispaced-phase resampling based on software, and the former is simpler.

In order to obtain absolute phase of spatial discontinuous object surface quickly, a phase unwrapping method based on encoding grating is proposed. In this method, a grating fringe image with encoding information is projected, the fringe order information which is needed for phase unwrapping is obtained, and then the absolute phase information of the whole measured surface is obtained. The three-dimensional information of the whole measured surface is obtained according to the phase-depth relationship. Compared with the phase unwrapping method based on the Gray code, the proposed method does not depend on gray information of the measured object and has better noise resistance. Only one additional encoding fringe is needed for the proposed method, so it is more suitable for three-dimensional measurement with high real-time requirement. The effectiveness and feasibility of the proposed method is demonstrated by experiments.

Aiming at the dual-beat-frequency light which is obtained by using fiber delayed self-heterodyne system, the theoretical model for power-spectrum of beat-frequency signal influenced by intensity fluctuation and phase noise of laser source is built. Based on the model, the numerical analyses and simulations are carried out. The results show that the short delay time between the two paths of laser can better decrease the influence of laser noise than the long delay time. When the delay time is shorter than the coherence time of the laser, the signal to noise ratio (SNR) of the beat-frequency signal can decrease as the laser linewidth and the intensity fluctuation increase. When the delay time is much longer than the coherence time of the laser, the laser phase noise becomes the main reason for spectral broadening of the beat-frequency signal. In addition, the power of the beat-frequency signal can decrease as the phase noise increases. The intensity fluctuations also make contribution to the broadening of the beat-frequency signal while increasing the power of the beat-frequency signal. When the delay time is long, the linewidth and power of the beat-frequency signal will change in accordance with the law of cosine as the delay time changes, and there are optimum operating points.

The beams of each emitter in the diode laser array are overlapped by spectral beam combination. Each emitter is locked at different wavelengths. Frequency conversion of the combined beam is conducted. When the beams from each emitter satisfy the nonlinear frequency conversion conditions, sum frequency generation of blue light can be obtained. The spectral combined diode laser array can increase the number of lasers participating in the nonlinear frequency conversion, and enhance the whole output power. In the experiment, a standard diode laser array is used. The output power of the spectral combined array is 18.2 W. The output power of the blue light is 93 mW, and the optical-optical conversion efficiency is about 0.51%. The feasibility of the multispectral frequency conversion of the spectral combined diode laser array is proved by the experiment.

In the laser beam stabilizing system, there are the broadband disturbance where energy is inversely proportional to the frequency and the narrowband disturbance at a particular frequency because of the transfer medium and vibration of the optical platform. In order to reduce the laser beam jitter caused by both kinds of disturbance, the control structure of fast steering mirrors (FSM) in series was put forward, and the control algorithm was presented, in which the first laser beam stabilizing system aimed to the narrowband disturbance, and the second laser beam stabiliting system resolved the broadband disturbance. So the disturbance can be restrained at the same time. The residual errors are compared between the proposed method and the classic control algorithm, and the simulation results and experimental results verify the availability of the proposed method.

The causation of edge distortion in conduction-cooled and end-pumped Nd∶YAG slab laser is analyzed and the experiment to suppress the slab edge distortion is conducted. The numerical simulation is done based on the experimental paramters indicating the result is consistent with the experimental one. The usage of the liquid epoxy-mucilage as heat conduction material to make a real-time cooling of the laser slab side can increase the energy ratio of fluorescence escaping from the laser slab side, which results in the reduction of the amplified spontaneous emission and the edge distortion peak-vallege value by 50%. This method possesses the advantage of enhancing the slab laser beam quality and output power.

The distribution of light field on silicon substrate of charge coupled device (CCD) is analyzed via mathematical modeling and experimental research. The atomic force microscope and scanning electron microscope are used to get the critical optical parameters, i.e. the micro lens surface function and the thickness of silicon dioxide thickening layer. The energy distribution of vertical incident planar light on the silicon substrate is simulated and it is compared with the experimental images of femtosecond laser illumination induced damages to CCD and they are consistent with each other. The research results shown that the coaction of micro lens and silicon dioxide thickening layer makes the laser energy almost illuminate at the sensing zone and the laser energy shows a dumbbell-shaped distribution.

Laser-induced breakdown spectroscopy (LIBS) is one of the effective ways to achieve online monitoring of solid material characteristics by detecting the particle flow directly. We investigated the different particle sizes of high purity quartz sand, whose stable flow was produced by high precision continuous powder feeding machine. 5 groups of quartz sand flow samples with different particle sizes were then ablated by a pulse laser directly to test the particle size effect and its modified method. The results show that slight fluctuation of mass flow has no obvious effect on the spectral intensity, while the fluctuation of particle size has significant impact on the spectral intensity. The spectral intensity increases with the decrease of particle size. By analyzing the time characteristics of Si spectral line intensity of each particle size, it is found that the effect of particle size is weak during the 2-4 μs delay time. Besides, the directly, synchronously excited and generated N spectral lines were used as an internal standard of silica spectrum, which may further weaken the effect of particle size, thereby obtaining the corrected spectral intensity which can characterize the particle flow. In this experiment, the correction effect of 343.76 nm line is best.

In order to meet the Brillouin frequency shift requirement of dual channel laser source for Brillouin optical time domain analysis(BOTDA) system, an optical fiber Brillouin frequency shifter is designed and placed in the probe pulse channel to make Brillouin frequency shift difference(about 11.2 GHz) between the probe pulse light and the frequency scanning light in another channel. By analyzing the frequency shifter output spectral linewidth narrowing principle, the Brillouin Stokes spectral output with narrow linewidth is formed by combining optical fiber stimulated Brillouin gain spectrum and specific ring cavity structure. The two performance indexes, including threshold of stimulated Brillouin scattering of ring cavity frequency shifter and light-light conversion efficiency, and their influence factors are analyzed. An experimental device of Brillouin frequency shifter with a seed source of 1551 nm and 9 km single mode fiber is set up. The experimental results indicate that the threshold value of stimulated Brillouin scattering is 2.3 mW and the wavelength change corresponding to the Brillouin frequency shift is about 0.1 nm, when the coupling ratio of directional coupler is 0.4 and light-light conversion efficiency is 49%. This optical fiber Brillouin frequency shifter meets the basic light source technical indexes of BOTDA system, which reduces the complexity and the cost of the system.

The L1 tracker has good robustness towards partial occlusion, but the L1 tracker is sensitive to the outliers from the target templates and has slow computation speed. Aiming at these two problems, we propose a two-stage sparse representation model and design a relevant fast solution algorithm based on the block coordinate optimization theory. At the first stage, the algorithm uses the locality-constrained linear coding to solve the coefficients of the target templates. At the second stage, the algorithm uses the soft shrinkage operator to solve the coefficients of the trivial templates. Based on particle filtering method, the representation model and the algorithm are combined to achieve the robust fast visual tracking. The standard image sequences are used to verify the proposed method, and the results of the experiment show that the proposed tracking method outperforms the state-of-the-art trackers in terms of the robustness and the tracking speed.

In order to improve the precision of pure monocular vision for the relative pose between two shields of double shield tunnel boring machine (TBM) during excavating process, this paper presents a new measurement system combining monocular vision and high-precision inclinometer sensors. Two inclinometer sensors are fixed with the camera and feature points separately. By multiple constraints of angles provided by inclinometer sensors and the monocular vision, the pose between front shield and back shield is measured with higher precision. In this paper, simulation shows that the feasibility of the system is validated and it has ideal precision. Afterwards, the experimental platform to simulate the pose of double shield TBM is established, and the accuracy verification experiment is conducted by a total station. The result indicates that the measurement precision is less than 3 mm and much better than that of the pure monocular vision measurement method, which means that this model can satisfy precise measurement requirements of double shield TBM poses during excavating process.

Binocular vision is a new kind of non-contact three-dimensional (3D) measurement technology, the calibration result will directly affect the precision of the 3D object measurement. Based on the iterative closest point (ICP) algorithm principle to obtain translation and rotation parameters between two point sets, a method is proposed by compensating binocular stereo calibration matrix to improve the precision on the basis of the results of traditional binocular pose calibration. The camera model, binocular vision measurement model and the basic steps of the ICP algorithm are introduced. The external parameters of binocular vision and the same target plane are used for obtaining binocular vision pose matrix, and a method is proposed by using the rotation and translation matrix of the two groups of point set to compensate binocular pose matrix based on ICP algorithm. The analysis model of corresponding target point coordinates projection error is established. Nine sets of calibration images including 5×7 points are collected, and the binocular vision calibration parameters are obtained, and the pose matrix using the ICP algorithm is compensated and nine sets of calibration error by using points coordinates projection error model are analyzed. Experimental results show that the application of ICP algorithm used to compensate the binocular calibration model could significantly improve the accuracy of binocular calibration.

For extracting the road and navigation line under the shadow environment, a road and visual navigation line extraction algorithm is proposed based on illumination invariant image segmentation and vote functions. The color illumination invariant image is acquired with orthogonal decomposition method. After the image segmentation, the road region is extracted through the structure of the vote function and road criterion. The navigation line is detected by scanning path location and the least squares fitting. The proposed method does not require a large number of samples to learn. Experimental results show that, compared with two existing algorithms, the proposed algorithm has obvious advantages in detection accuracy, speed and complexity, it can effectively solve the road and navigation line extraction under the shadow environment.

Aiming at camera calibration with one dimensional (1D) objects, a new mathematical model of a novel method for camera calibration is proposed, in which the world coordinate system is established with the 1D object. Generally, assuming that the 1D calibration object is located along the X-axis of the world coordinate system and the 1D homography matrix between 1D calibration object and its image plane is defined. The basic constraint for 1D camera calibration from a single image is derived. The closed-form solution is estimated by linear least-square method based on the basic constraint equations and the final calibration results are obtained by minimizing the projection error of the points. Simulation results with real experiment show that the proposed method is valid and feasible. The experimental results indicate that compared with traditional method, the proposed novel method has the characteristic of higher closed-form solution precision and the image coordinates of the fixed point are not needed to be estimated when the fixed point is invisible.

Photonic crystals (PC) with low emissivity have high reflectance, and they will become bright targets under strong radiation from high temperature environment. Further researches on PC characteristics are made in order to let PC have adaptive capacity to environment and fuse with background well within a pretty broad luminance range. Six PCs, with emissivity of 0.116、0.212、0.307、0.519、0.606 and 0.718, are designed and made by the method of changing PC period. PCs are jointed into four PC pattern paintings (PCpp), and they are covered on the surface of simulation target. The target and background are observed by the 8～14 μm thermal imager, and their mean radiant temperatures of each time point are recorded. Euclidean distance between target and background and camouflage efficiency of the target under this background are calculated by radiant temperature. Compared with the results, it is found that camouflage efficiency is 76.92%, when the temperatures of PCpp with emissivity of 0.212、0.307 and 0.606 are in the range of 292～302 K, the Euclidean distance between the mean temperature of PCpp and the temperature of the grass background is 12.55 K, and the limit temperature difference ΔT0 is 4 K, which can make the target and the background fuse well.

In order to collect images effectively with a corneal topography based on the Placido disk, a system with a symmetrical achromatic lens and a collimating illumination lens is designed according to characteristics of human corneal and CCD plane array parameters. The initial structure of the imaging lens is calculated based on the theory of primary aberration and the PW method. The collimating illumination lens parameters is designed by paraxial ray trace equations. The imaging system is optimized with the Zemax software. The imaging lens structure is composed of four lenses in two groups, its effective focal length is 20 mm, back working distance is 19.2 mm, full field of view is 8°, relative aperture is 1/3, and maximum optical total track is 20 mm. The modulation transfer function in all fields is larger than 0.3 at resolution of 66 lp·mm－1 and the full field-of-view distortion is less than 0.5%. The system is characterized by its simplicity, compactness, easy processing, low cost and high imaging quality, which meets the requirements of the whole system very well.

To solve the problems in conventional design of three-mirror system such as complicated initial structure solution and slow convergence when using aspheric surfaces, a design for off-axis three-mirror optical system based on Wassermann-Wolf differential equations is proposed. According to the law of reflection and sine condition, the Wassermann-Wolf differential equations for solving coaxial three-mirror initial structure are derived. The coaxial three-mirror initial structure with good image quality is obtained by fitting Wassermann-Wolf surfaces with polynomial. An off-axis three-mirror optical system is achieved with long effective focal length (1200 mm), wide field of view(18°×4°), and large relative aperture (F number is 4). The modulation transfer function is over 0.5 at 50 lp/mm in every field of the system. Result of the design indicates that this method based on Wassermann-Wolf differential equations is simple, effective, fast in convergence, and it provides a good starting point for the design of three-mirror optical system. Besides, the primary mirror is of conic surface, and both the second and tertiary mirrors are aspheric. The three reflectors are neither eccentric nor tilted, so the fabrication cost as well as the alignment difficulty are effectively reduced.

Zoom system based on liquid crystal lenses can realize zoom without moving elements. This zoom working mode is applicable to some specific imaging systems, and has attracted much attention in recent years. The effects of liquid crystal lens parameters including zoom range and clear aperture on zooming performance of zoom system are studied. The calculation formulas of the maximum zoom ratio and the maximum field of view of the liquid crystal lens zoom system are theoretically obtained. According to the theoretically calculated structure, the zoom curve expression of the zoom system is obtained. The zoom curve shows that the zoom ratio grows faster and the focal length varies more sensitively when the system changes from short focus to long focus. Using the liquid crystal lenses developed by the University of Shanghai for Science and Technology, we design a Gauss model of liquid crystal lens zoom system with zoom ratio of 6 and full field of view of 60°. The design does not only verify the theoretical derivation, but can also be used as the initial structure of an actual liquid crystal lens zoom system.

This paper presents the design of a new Fresnel lens for GaInP/GaInAs/Ge multi-junction solar cells, with which uniformity irradiance distribution can be realized within the broadband solar spectrum from 300 nm to 1800 nm. By actual tests, the quantum efficiency spectrum of GaInP/GaInAs/Ge multi-junction solar cells and refractive index dispersion curve of silicone, the body material of the lens are obtained. On this basis, the new Fresnel lens is optimized by combining the multi-wavelength and multi-focus method. Based on this optimization method, the lens model is set up with geometrical concentrator ratio 625× and ring width 0.3 mm, and calculation models for concentrating performance parameters including optical efficiency and uniformity are established. The concentrating performance of the new Fresnel lens is analyzed by Monte-Carlo ray-tracing simulation approach and experimental testing. Results indicate that in the broadband solar spectrum from 300 nm to 1800 nm and within the spectral response band of three subcells, uniformity is well achieved with high optical efficiency. The uniformity is higher than 75%, and the optical efficiency is more than 80%.

We propose polarization selective three-equal-power splitters for transverse-electric (TE) and transverse-magnetic (TM) waves based on two-dimensional photonic crystals. The structures are constructed by square-lattice cross-shaped photonic crystal waveguides. The finite element method and the Nelder-Mead optimization method are used to calculate the properties of the structures and obtain the optimized parameters, respectively. The results show that the power splitters are polarization selective when different polarization-selective defects are set in the input channels. For the TE power splitter, TE waves can enter the splitter and transmit in it, while TM waves cannot enter it; for the TM power splitter, the situation is just reversed. In addition, the power splitters can obtain the identical power output at various ports when power-control defects are set at the cross junction of the waveguides. With optimized parameters, the total transmission efficiency of the TE and TM power splitters can be up to 99.48% and 95.53%, respectively. Moreover, it is found by wavelength scanning of the structures that these two splitters can work in a relatively wide wavelength range while keeping good performance.

Considering the requirement of monochromaticity and tunubility for resonator used in on-chip optical interconnect source, we design and make a tunable silicon reflection cavity mirror based on microring resonator, using complementary metal-oxide-semiconductor technology and silicon material-on insulating substrate. The performance of the reflection cavity is analyzed by the transfer-matrix method, and we find that the reflection cavity shows good properties in sharpness and extinction ratio. The experimental results show that the reflectivity of the reflection cavity can reach 90% at the wavelength of 1549 nm, the quality factor is 3×104, and the free spectral range (FSR) is 9.6 nm. By applying the thermo-optic modulation to the microring resonator, the wavelength tunability in FSR can be realized within the power range of 0-40.5 mW.

We established an angle-resolved spectral measurement system based on coaxial rotation arms to construct the optical characterization on plasmonic structures. Two arms slew around the sample stage surface to achieve directional stimulation and collection; and a standard rod through two slewing bearings was used as the constraint and allowed radial relative movement between the pivot arm and electric turntable, which ensured the coaxial rotation to get accurate angle information. The spectrophotometer was calibrated by back-propagation neural network algorithm to ensure accurate wavelength information of angle-resolved spectrum. This system had altitude angle from 7.9°to 89°, and the angular resolution is 0.1°. Experiments on one-dimensional periodic gold grating and two-dimensional periodic structure on gold film demonstrated the capacity of the system in angle-resolved spectroscopic characterization for plasmonic samples in different environment, at different altitude angles and different azimuth angles.

Mueller matrix decomposition method and Mueller coherence matrix method for the complete depolarization characteristics of Mie scatterers are compared. The parameters of the depolarization characteristics are discussed. It is found that when the depolarizing medium doesn’t contain other polarization characteristics, the difference between the general polarization-maintaining indexes calculated by decomposition method and coherence matrix, and the standard value will increase with the deviation degree of anisotropy coefficient of depolarization along the medium’s principal axis. The maximum divergences are 0.16 and 0.07 and the relative divergences are 33% and 15% respectively. Because of the depolarization anisotropy in Mie scatterers, the polarization-maintaining index-entropy chart can also be used to denote the depolarization anisotropy qualitatively, as well as the anisotropy coefficient of depolarization. When the Mie scatterers show other polarization properties, for example the birefringence and the optical rotation, the linear depolarization will show the anisotropic property. At the moment, the linear depolarization anisotropy factor should be introduced to completely depict the depolarization characteristics of Mie scatters.

The atoms are driven by classical field introduced in the cavity quantum electro-dynamic model. By setting the relationship between frequency detuning of atom-cavity field and classical field driven strength, the transformation from the effectively Jaynes-Cummings model to the anti-Jaynes-Cummings model is achieved. The dynamic process of the whole system can be controlled. The entanglement dynamic behaviors of three-atom Greenberger-Horne-Zeilinger (GHZ)-type and W-type entanglement states in different effective atom-cavity field interaction models are discussed. The results show that the three-atom entanglement state in dynamic process can change from entanglement-sudden-death to no-entanglement-sudden-death with the assisting of classical field, so the phenomenon of entanglement-sudden-death can be inhibited. The entanglement robustness of the three-atom GHZ-type and W-type entanglement states in dissipative cavity is explored in the evolutionary process. The effective atom-cavity interaction model of the three-atom GHZ-type and W-type entanglement states are obtained in dynamic process in which the strongest robustness can be acquired.

To study the property of quantum radar cross section (QRCS) of curved surface target, the probability wave functions of single-photon and two-photon are introduced according to the quantum description of interaction between photon and mirror matter, and the cylinder surface is used as the simulation model. The QRCS analytical expressions of single-photon and two-photon are deduced on the basis of the definition of classical radar cross section (CRCS), and the QRCS definition of multiple photons is extended and derived. The different physical natures and mutual relationships between QRCS and CRCS are also analyzed. Simulation results show that the two-photon QRCS is aberrant in millimeter wave band under different incident angles, and the single-photon QRCS has better performance. Compared with CRCS, QRCS has higher main-to-sidelobe ratio.

According to current problem that the time-varying systematic error of image geometric positioning is difficult to be compensated, an algorithm based on Fourier series model is proposed to achieve the on ground compensation of time-varying systematic error. The digital orthophoto map/digital elevation model reference data of geometric calibration field is used for accuracy verification. The data of Yaogan-26 satellite launched in December 2014 is analyzed, the results show that, this designed on ground compensation model of time-varying systematic error can effectively improve the image geometric accuracy under no ground control points, and the image geometric positioning accuracy after compensation can be increased about 40%.

The Raman spectra of 35 stone samples (13 Shoushan stones and 22 Laos stones) are measured by a self-developed portable Raman spectrometer Hx-Spec, which is excited by a 785 nm diode laser and the spectrum range is 200-2700 cm-1 with a resolution of 6 cm-1. A multioariate model is established by combining the principal component analysis (PCA) and the linear discriminant analysis (LDA), a discrimination sensitivity of 86.7% and a specificity of 100% are achieved in separating Laos stone from Shoushan stone, while the performance of corresponding receiver operating characteristic (ROC) curve is 0.977. Besides, a discriminant accuracy achieves 87.5% after 8 new samples are added as a validation. These results demonstrate that the utility of portable Raman spectrometer combined with chemometrics provides a new strategy to discriminate the Shoushan and Laos stones.

A monochromatic imaging system with two-dimensional resolution is designed based on spherically bent crystals. Ray tracing simulation to the imaging process is conducted with the usage of optical simulation software. The backlit imaging to the Au meshes is conducted and a monochromatic mesh image with an energy of 8.048 keV and a spatial resolution of 9 μm is acquired. On the SG-II updated laser facility, with this imaging system, the Kα self-luminous monochromatic image of two-dimensional cone target is successfully acquired. The results show that this imaging system is capable of hot electrons diagnostics in the fast ignition experiments.