A depolarizing dichroic beam splitter, which works in the waveband from 350 nm to 1700 nm is designed and fabricated for broadband imaging spectrometers. Based on the working characteristics of the imaging spectrometer, the spectra in near-UV, visible and near-infrared bands are effectively separated, and the signals spread to their respective focal planes and are received by different detectors, respectively. In order to achieve high reflectance from near-UV to visible, two thin film materials are selected to structure four reflectance stacks. The linear polarization sensitivity is hard to control because of absorption of the thin film materials, and the problem is solved by adjusting the order of stacks. The spectra in the transmission band are smoothed by the non-regular film matching. The optical efficiencies in the reflection and transmission bands are as high as 97% and 91%, respectively, and the linear polarization sensitivity is lower than 1.5%.

With the feedback technique, the spatiotemporal chaos is controlled in the photorefractive ring oscillator. Numerical simulation results show that the fixed value feedback and variable feedback technologies both can realize the control of spatiotemporal chaos. When the photorefractive ring oscillator system parameters are confirmed, the control of spatiotemporal chaos is realized based on the fixed value feedback. In addtion, the system has the minimum feedback coefficient and the maximum feedback light intensity to realize spatiotemporal chaos control. So the reasonable feedback coefficient and feedback light intensity must be chosen in order to control the spatiotemporal chaos. The feedback technology can not only be used to realize the one-dimensional spatiotemporal chaos control, but also the two-dimensional control, and simultaneously the two control results are similar.

Combined with the discrete sine transform (DST) and discrete cosine transform (DCT), a novel DST/DCT direct current bias-discrete multitone(DC-DMT) modulation scheme is proposed. This method is able to expand the number of independent subcarriers without increasing the complexity of system, and it is expected to improve the transmission rate of visible light system. The bit error rate (BER) expression of the modulation scheme and the complementary cumulative distribution of peak-to-average power ratio(PAPR) are derived. The effects of clipping noise on the BER performance of DMT, direct current-biased optical-orthogonal frequency division multiplexing (DCO-OFDM) and asymmetrically clipped optical-orthogonal frequency division multiplexing (ACO-OFDM) visible light systems are analyzed. The results show that the theoretical BER is consistent with the simulation results, and the BER performance of the proposed scheme is better at the same transmission rate compared with that of other methods. The distribution of PAPR is independent of the modulation order but increases with subcarrier number N. When N is larger, the theoretical conclusions match the simulation results. At the same transmission rate, the simulation results show that the BER performances of DST/DCT DC-DMT and DCO-OFDM are similar in low signal-to-noise ratio (SNR), which are better than those of PAM-DMT, DC-DMT and ACO-OFDM; however, the BER performance degrades in high SNR due to the clipping noise.

In astronomical detection, the measurement precision of radial velocity in Earth-like planet detection is required to reach 10 cm/s. The spectrum drift caused by circular fiber scrambling is becoming a major factor that influences the measurement precision of radial velocity. The sectional fiber transmission systems of circular fiber combined with polygonal fiber are proposed to improve the scrambling property of circular fiber. The spot quality of fiber output field is evaluated by an optical system for testing spot quality of far field and near field. The far field and near field distributions of sectional fiber transmission systems, which are consisted of circular fiber, circular fiber combined with square fiber, and circular fiber combined with octagonal fiber, are studied under different coupling conditions. The scrambling gains and energy variations of these fiber transmission systems are analyzed. The results show that the scrambling property and the system stability are improved by the sectional transmission system of circular fiber combined with polygonal fiber. The coupling energy loss is caused by large incidence shift on the condition that the core diameter of polygonal fiber is smaller than the core diameter of circular fiber, and the conservation of the energy holds on when the core diameter of polygonal fiber is larger than or equal to the core diameter of circular fiber. The transmission system of circular fiber combined with octagonal fiber, which is with a small mass center offset in the near field and a large scrambling coefficient, can decrease the spectrum drift induced by coupling error, and increase the measurement precision of radial velocity.

In the coherent laser communication systems, the instrumental polarization aberration of the optical system can change the polarization state of the received signals and reduce the heterodyne efficiency between the local oscillator beams and received signals. In order to quantitatively analyze the polarization properties of the optical system, the three-dimensional polarization ray-tracing algorithm is proposed. Based on a large aperture coherent laser communication testing platform system, the polarization ray tracings of the communication channel are performed by means of this algorithm, and the influences of the polarization aberration on the polarization state of the circular polarization signal are discussed according to the calculated polarization transformation matrices. The polarization characteristics of the communication system of the testing platform are verified through the experimental platform.

Atmospheric molecules and aerosol particles have strong scattering effect on ultraviolet (UV), and the non-line-of-sight communication can be realized by using UV as the information carrier. The study of the pulse broadening effect in UV communication is very important for reducing the intersymbol interference and improving the system transmission rate. Based on the Monte Carlo method, the multiple scattering transmission model of the non-line-of-sight UV in the noncoplanar communication system is established. The whole process that UV is emitted from the transmitter and arrives at the receiver after multiple scattering is simulated. The results show that the full width at half-maximum of the impulse response of non-line-of-sight UV in the noncoplanar communication system will increase with the increasing elevation angle of the transmitter, the elevation angle of the receiver, and the deflection angle of the receiver. The contribution of multiple scattering to the pulse broadening increases with the increasing elevation angles of the transmitter and the receiver. The maximum code rate of the system will be reduced with the increasing elevation angle of the transmitter and the receiver by the on-off keying modulation mode.

According to the characteristics of the all-fiber lidar, the transmitting and the receiving optical systems are designed and optimized. Aiming at the characteristics of the laser Gauss transmission, the extended target and the optical fiber transceiver of the all-fiber lidar optical system, the transmitting antenna gain and the target reflection cross-section in the lidar equation are modified, and the fiber reception efficiency is introduced. The modified transmitting antenna gain is inversely proportional to the square of the target spot size. The radar reflection cross-section of the diffuse reflection target depends on the target reflectivity and the laser incidence angle. The relationship between the echo power and the core diameter of the reception fiber is explored in experiment, and the optimum fiber core diameter is obtained. The modified lidar equation can calculate the laser echo power from the optical fiber transceiver accurately and provide precise theoretical support for subsequent signal processing.

Due to the inter symbol interference between multiple reference point sources in the positioning system, the positioning accuracy of the indoor visible light communication positioning system is decreased. Therefore, a positioning algorithm of visible light communication based on code division multiple access (CDMA) modulation is proposed. The identity (ID) information of every light emitting diode (LED) source is broadcasted by using the orthogonality of the spread spectrum code. The inter symbol interference is overcome and the capacity of the channel is enhanced by using the spread spectrum. At the receiver end, ID information and the signal strength of each LED are distinguished by adaptive filters. The location area of each LED and the distance between receiver end and each LED can be determined according to the ID information and the signal attenuation intensity, respectively. The positioning of the receiver can be realized by using the received signal strength (RSS) triangulation positioning algorithm. Furthermore, the receiving gain is improved by means of diversity reception technique, and finally the positioning accuracy is improved. The simulation result shows that the maximum error of the proposed positioning system is 6.18 cm, and more than 88% of the positioning point can be of the positioning accuracy less than 5 cm. The system not only achieves a good positioning accuracy, but also has a good stability and is easy to control, which will have broad application prospects.

A temperature insensitive curvature sensor of the photonic crystal fiber (PCF) based on core-offset splicing and waist-enlarged fiber taper is presented. The sensor can measure the curvature magnitude and direction. The SMF-PCF-SMF structure is fabricated by drawing a length of PCF fused and spliced between two single-mode fibers (SMF). One end-face of the PCF is core-offset spliced with a SMF, so that the sensor can form an asymmetrical structure on the axial direction. When the sensor bends on two symmetrical directions, the red shift and blue shift phenomena of the transmission spectrum appear obviously. The other end-face of the PCF excessively spliced with another SMF forms a waist-enlarged fiber taper, and finally the Mach-Zehnder interferometer is obtained. Curvature and temperature response characteristics of the sensor are studied experimentally. When the curvature is in the range of 0.12 m-1 to 1.06 m-1, the results show that the spectrum is red-shift in concave bending and blue-shift in convex bending. Besides it has a good linearity. The sensitivities are 11.22 nm/m-1 and -13.62 nm/m-1, respectively. In the range of 20 ℃ to 80 ℃, the temperature sensitivity of the sensor is only 1.63 pm/℃, so it shows a temperature insensitive property. Compared with the traditional fiber sensors, the cross sensitivity of temperature and curvature simultaneous measurement can be avoided in the proposed sensor which also has advantages including easy fabrication, simple structure and high sensitivity. It can be used in such fields as industrial production, building monitoring and aerospace.

A transmission scheme of atmospheric laser communication based on depolarization ratio detection is proposed to solve the problem that the intersymbol interference in the communication link is caused by the multipath scattering effect in atmospheric laser communication. A Monte Carlo simulation is carried out by using the technologies of photon tracing and Stokes vector transform. The correspondence relationship between the depolarization ratio of received light and the optical depth of clouds is obtained through setting different physical depths and extinction coefficients of clouds. The relationship between the depolarization ratio of received light and the average pulse broadening time is obtained based on the Stotts formula. An optimal communication rate scheme under the multipath effect is proposed. This scheme can detect the depolarization ratio at the receiver of the laser communication system directly, evaluate the multipath intensity in atmospheric channel environment effectively, and achieve the largest communication transmission while ensuring the quality of laser communication. The research has theoretical guiding significance and application value in communication link optimization of satellite-ground laser communication and adaptive laser communication.

The narrow band filter is used in spatial heterodyne spectrometers to limit the spectral range of the instrument and to avoid spectral overlapping. Due to the change of the filter transmittance with incidence angles, the emergent optical field from the collimating system is non-uniform at different wavelengths. The optical field non-uniformity mechanism is deducted theoretically, proving that modulation of filter causes convolution with a wavelength-related modulation function in restoration spectra and results in variation in full width at half maximum (FWHM) of monochromatic spectrum with wavelength. A simulation is carried out based on the theoretical formulas and the spatial heterodyne spectrometer parameters in laboratory, indicating that there exists influence of filter modulation that appears in concavity at shorter wavelength and convexity at longer wavelength. Monochromatic scanning experiments are performed in laboratory, and the measurement results are consistent with those of theoretical analysis and simulation. An enveloping line fitting correction method is proposed. The variation in FWHM of the instrument line function decreases from 16.7% to 0.2% after correction, suggesting that the influence of modulation function of filter on restored spectra is eliminated effectively.

Cube-corner prism is often applied as cooperative beacon in electro-optical distance measurement and photoelectric tracking. In some special applications, the beam reflected by the cube-corner prism should be with a divergence angle to fully cover both the laser and detector at different locations of the far field. Due to the fact that normal cube-corner prism cannot diverge a beam, the differences of the beam exit point and the incident point of the cube-corner prism are considered and the divergence of the reflected beam can be realized by installing a planoconcave lens in front of normal cube-corner prism. The feasibility of the divergence of the reflected beam by using planoconcave lens and normal cube-corner prism is analyzed by the theoretical analysis method and the geometrical ray-tracing simulation method. The quantitative relationship between the divergence half angle of reflected beam and the parameters of both the incident beam and planoconcave lens geometry is studied as well. Both the theoretical and simulation results show that the divergence half angle of the reflected beam increases quasi-linearly with the incident beam radius when the incident beam radius is less than the radius of the planoconcave lens. The smaller the curvature of planoconcave radius is, the greater the divergence half angle of the reflected beam will be.

This paper presents a new approach for laser linewidth measurement-loss compensated recirculating delayed self-heterodyne interferometer (LC-RDSHI), which is insensitive to the system parameters. Through the derivation of its system output power spectral density function and simulation of beat frequency power spectrum, the characteristics of system parameters insensitivity for proposed method are analyzed and discussed. On this basis, we build the appropriate experimental device and observe the effects of system parameters on the output power spectrum of LC-RDSHI, and we find that the experimental observations agree with theoretical analysis. Besides, based on different experiment system parameters, we make a comparison of linewidth measurements between the proposed method and conventional LC-RDSHI. The results indicate that the system parameters insensitive LC-RDSHI has higher linewidth measurement accuracy, its measurement process is easier, and therefore, it has better application prospects.

In the scheme of radial smoothing based on the optical Kerr effect, pump laser pulse train uses optical Kerr effect of nonlinearity medium to add periodical spherical phase modulation, which makes the speckle inside the focal spot of the laser beam in far field sweep periodically at radial direction, and the uniformity of the focal spot in far field is improved. To analyze the influence of temporal characteristics change of the pump laser on beam smoothing effect, a theoretical model of the radial smoothing scheme has been established, and the time characteristic parameters of the pump laser has been analyzed and optimized. The results indicate that, for the given delay time between pump photon pulses, the sub-pulse with either too large or too small pulse width will reduce the irradiation uniformity of laser beam in far field. Meanwhile, with the increase of the pulse width of sub-pulse, the volatility of irradiation uniformity of laser beam in far field with integral time is trending toward stability relatively. Thus, the relatively large pulse width of the pump laser would be beneficial to obtain a more stable smoothing effect under the condition that the obvious beat wave effect should be avoided as far as possible. The time synchronous precision between the laser beam and the pump laser has a significant influence on the initial beam smoothing effect. For the pump laser of about one fifth period of the pulse train in advance, a better smoothing effect can be obtained in a relatively shorter integral time. In addition, for different temporal shapes of the pump laser, different smoothing effects can be achieved. When the temporal shape of the pump laser is triangular, the radial direction sweeping speed of the speckle inside the focal spot is relatively stable, and the radial smoothing effect and its stability can be improved effectively.

Selective laser melting (SLM) technology is used to fabricate the CoCrMo alloy standard specimen. With the casted CoCrMo alloy and SLM manufactured CoCrMo alloy respectively combined with the ultrahigh molecular weight polyethylene (UHMWPE), the wear-resistance experiment is conducted. The experiments show that, under the four kind of lubrication conditions including dry friction, physiological saline, artificial saliva, and calf serum, the friction coefficient of the SLM manufactured CoCrMo alloy is always less than that of casted CoCrMo alloy. In addition, under different lubrication conditions, the wear mechanisms of the SLM manufactured CoCrMo/UHMWPE and the casted CoCrMo/UHMWPE are different.

The influence of electromagnetically induced transparency (EIT) on the cavity ringdown spectroscopy (CRDS) is analyzed theoretically. Utilizing the optical pumping effect of EIT in a three-level V-type structure which can increase the transmittance of the EIT medium, we propose a program to improve the CRDS performance. In the experiment, a V-type EIT is constructed with the D2 line of 87Rb, and the ring-down time and sensitivity of the CRDS system are improved under appropriate light intensity. Finally, the ringdown sensitivity is enhanced to 1.45 times of the original value.

Based on the homemade frequency-swept laser source with a narrow instantaneous line width, the main factors influencing the laser instantaneous line width are investigated by numerical model and experiment. The research results indicate that the instantaneous line width of the frequency-swept laser increases with the increment of dispersion, and the filter bandwidth and the signal pattern loaded to the filter both influence the instantaneous line width. At the same time, the intra-cavity mode competition can ensure a narrower instantaneous laser line width.

In breast diffuse optical tomography, the introduction of the L1-norm regularization greatly improves the quality of the reconstructed image. However, the non-differentiable property of the objective function leads to exceeding difficulty in the optimization process. A new reconstruction method based on the L1-norm regularization with the non-negative restriction is proposed. To easily solve the first-order gradient of the objective function, the non-negative prior information is introduced. The optimization process is then well simplified and accelerated. Both the numerical simulations and the phantom experiments demonstrate that this new method can obtain much better results than the conventional regularization methods, and its process is more simple and faster.

Optical polarimetry is a noninvasive glucose monitoring technique which can be potentially used to ascertain blood glucose levels through measuring the aqueous humor glucose levels in the anterior chamber of the eye. One major limitation of the polarimetric approach as a means to noninvasively measure glucose levels is time-variant corneal birefringence caused by motion artifact. We design a real-time, closed-loop, dual-modulation, multi-wavelength polarimetric system for glucose measurement by using an isolated human cornea ex vivo clamped on an artificial anterior chamber. Eye coupling devices are utilized to prevent bending of the light through the anterior chamber due to index mismatch between air and aqueous humor barrier. The polarimetric setup for glucose measurement ex vivo is presented and the system predicts the glucose concentration with standard error of 18.9 mg/dL and 15.2 mg/dL in the presence of birefringence with motion at two runs. The results indicate that polarimetry can effectively be used to minimize the effect of corneal birefringence in vivo, and helps to accurately measure glucose concentration in the aqueous humor of the eye that is correlated with blood glucose levels.

A high resolution single circle absolute coding technique is proposed to improve angle measure resolution, reduce disk dimensions, and overcome the shortcoming of low speed in traditional image encoder. The single circle absolute coding method is proposed by analyzing the relationship between disk reticle and resolution, a decoding method is proposed by using collimation light source and linear array image sensors, and the high resolution disk and decoding circuit are designed based on the proposed method. In the experiment, the diameter of single circle disk is 38 mm, the digit is 10, and the decoding of 10 bits coding is achieved. The proposed method has faster response frequency than the traditional coding method with the array image detector.

Based on the low-vibration cryostat, a Mach-Zehnder laser interference microscopic system used for parameter measurement of cryogenic targets is developed. With the consideration of light diffraction effect, a complete formula for describing the variation of optical-path difference with incident angle is deduced. In a low temperature environment and when the fuel solidifies or gasifies completely, the interferograms are acquired respectively with the existence of fringes at the target pellet center. With the fringe shape analysis method and the optical-path difference formula, the target pellet thickness and the fuel gas concentration within it are calculated, respectively. In addition, based on the non-destructive method, the real-time characterization of measurement results of gas concentration is conducted. The relative error between the results from the above two ways is less than 5%.

According to the large scale spatial objects real-time attitude measurement demand in the process of large equipment assembly and docking in the field of aviation and aerospace, a new method for attitude measurement is put forward based on orthogonal cylindrical imaging, disassembling and reconstructing the function of two-dimensional angle measurement which is provided by the existing array image sensor using in photogrammetric measurement system. The method makes full use of the advantages such as high one-dimensional angular resolution, fast acquisition speed and simple treatment of linear array CCD, and simplifies the camera structure with cylindrical orthogonal imaging optical path. A non-parametric calibration method is used to correct the aberration of the imaging cylindrical. In order to solve the coordinate synchronization problem during space object attitude measurement, the real-time recognition tracking method is researched based on extended Kalman prediction to realize parallel measurement of multiple targets, and then realizes the real-time attitude determination through attitude calculation model based on Rodrigues parameters. Experimental results show that space three-dimensional coordinate measurement accuracy is better than 0.5 mm, and the maximum measurement errors of space object pose solution in yaw, roll and pitch directions are 0.20°, 0.12° and 0.23° respectively. The proposed method has high accuracy of attitude measurement.

Null interference technology based on the computer generated hologram (CGH) has been used to measure the aspheric surface. For measuring deep aspheric surface with great deviation degree and high slope, it is difficult to fabricate CGHs with high spatial frequency. We proposes a method combining CGHs with low spatial frequency to achieve the function of a single high-spatial frequency CGH in deep aspheric surface test. A one-dimensional linear grating model is introduced to establish the relationship between the spatial frequency of the single CGH and that of CGHs combination, and the initial phase of the CGHs combination can be obtained based on the relationship. The optimal phase is solved out by optimization. For the deep aspheric surface with maximum departure of 193.434 μm and slope of 75.788 μm/mm, the wavefront errors for the single CGH and the CGHs combination are less than λ/250. The maximum spatial frequency of CGHs combination is reduced by 50% compared to that of the single CGH. Auxiliary alignment CGH is designed to reduce the adjustment errors, and the influence of tilt error, decentration and axial deviation on the detection accuracy is analyzed.

The influence of atomic coherence and quantum coherence on the hybrid atom optomechanical system is studied. The Langevin equation is solved by the perturbation method and the optical cavity input-output theory, and the response function of the hybrid atom optomechanical system to weak probe field is obtained. The influence factors, including the coupling strength between the cavity mode and the atom system and the quantum interference effect on the output properties of the hybrid atom optomechanical system, are analyzed. It is found that the output properties of the hybrid atom optomechanical system can be controlled by controlling quantum interference effect. By changing the intensity of the controlling field, the width of the transparent window of the hybrid atom optomechanical system can be changed, and the absorption spectra of the optomechanical system modulated by the atom absorption spectrum is obtained. The probe field can be amplified in the center region of the transparent window of the hybrid atom optomechanical system. When the detuning of the controlling field or the coupling field is changed, the location of the transparent window of the hybrid atom optomechanical system can be controlled.

The screen of solid-state volumetric three-dimensional (3D) display system is based on a polymer stabilized cholesteric texture normal-mode （PSCT） shutter array structure. The nonlinear variation of haze and transmittance of the shutter causes the image luminance deviation, as well as the image crosstalk between adjacent shutters. The photoelectric response characteristic and driving method of the PSCT shutter array are analyzed. Based on the analysis, the image luminance variation function of shutter array is derived, and thus the luminance of sub-frames and grayscale deviations are calculated. Grayscale correction is implemented through adjusting the driving timing of shutters and reallocating sub-frames, combined with Gamma correction. 3D images before and after grayscale correction are displayed on the solid-state 3D volumetric display system. Experimental results indicate that the proposed method can correct the grayscale deviations efficiently and eliminate the image crosstalk between adjacent shutters mainly at the cost of a minor luminance loss （about 6%）. The proposed approach can improve the 3D image quality to some extent.

The vertical concentration distribution of lower-troposphere (2 km below) atmospheric CO2 in Hefei western suburb is measured by Raman lidar system. By system calibration and moving average of the data, the vertical concentration profiles of atmospheric CO2 are retrieved. Through statistical analysis of the retrieved results of lidar observation data from July 2014 to December 2015, the variation patterns of lower-troposphere atmospheric CO2 vertical concentration distribution in Hefei western suburb are initially obtained. The results show that the CO2 vertical concentration distribution of lower-troposphere decreases with the increase of altitude, the concentration is rather high and changes intensely under near-surface 150 m, but the concentration of atmospheric CO2 above 300 m is getting stable. The lower-troposphere CO2 vertical concentration distribution shows obvious connection with the season, with a minimum in summer and a maximum in winter. The lower-troposphere atmospheric CO2 vertical distribution shows some correlation with the month, and the whole CO2 vertical concentration goes up with a rate of about 2×10-6 per year. Through the experiments, it is found that the CO2 vertical concentration shows a non-monotonical decrease with the altitude increase. There exists a CO2-rich area from 300 m to 700 m, and the CO2 concentration of this area decreases as the sky turns bright.

Based on the side-scattering lidar equation and Mie scattering theory, the relational model of PM2.5 concentration and side-scattered light intensity is built, and a method for real-time monitoring near-ground PM2.5 concentration based on charge-coupled device(CCD) is proposed. A side-scattering lidar device is designed, which uses the laser with 532 nm wavelength as light source and CCD as the receiver. The side-scattering echo signal with scattering angle from 15° to 45° is measured with this device. The gray value matrix is extracted from the echo signal image, and the light intensity distribution in the echo signal image is analyzed. Compared with the measurement results provided by SHARP, a PM2.5 monitor from Thermo Fisher Scientific Company, the formula between PM2.5 concentration and total energy of three gray levels is fitted with a fitting degree better than 0.97. The device has the characteristics of convenient operation, convenient movement, real-time monitoring and low cost. It has a higher precision and practicality than the backscatter lidar in near-ground, which contributes to establish the distribution and movement model of PM2.5 pollutants and make a map of pollution.

The main method to improve the resolution of optical system is enlarging the pupil of the optical system, and segmenting sub-mirrors to get an equivalent large diameter primary mirror is a common way to enlarge clear aperture. After the deployment of sub-mirrors for segmented mirrors optical system on orbit, there is deviation between deployment position and the designed position, which is called position error. The error determines the imaging quality of the optical system. So it is necessary to analyze the precision of the position of sub-mirrors. Optical software is used to model the segmented mirror optical system, and the relationship curves between position error and the system′s imaging quality is got by adjusting position error of six degrees of freedom for sub-mirrors. The results show that root mean square (RMS) values generated by the same position error are different when sub-mirrors are at the different positions. The middle mirrors are sensitive to the movement along X axis direction, and the outer ones are sensitive to the movement along the Y axis direction. Two methods are used to distribute the errors into the sub-mirror position error. One is distributing the position error to each sub-mirror alone. Another is distributing the same position error to each sub-mirror. The results show that the former way has a more relax position error when the generated wavefront errors are the same.

A parametric design method for flexure supporting of the optical space remote sensor is presented to raise the design efficiency. The demands of flexure supporting deformation in the cases of temperature changes and assembly error are analyzed separately. The compromise programming method is used to establish optimal function of flexure supporting. Taking the flexure supporting used in the primary mirror of optical space remote sensor as example, the parametric design is provided in detail. After parametric design, the fundamental frequency of the flexure supporting is 88.8 Hz, the root mean square (RMS) of the mirror surface is 5.3 nm, when the temperature rise 4 ℃. The RMS is 12.9 nm when the assembly error is 0.1 mm, the RMS is 5.0 nm when 1 g gravity worked. The performance of flexure supporting significantly develops and all the design meets the targets. Computer automation design is applied during the design process, which greatly reduces the investment of human beings and the cycle of design at the same time.

In order to find a more accurate calculation method of relative illumination of lens image plane in a wide-angle lens system, the limitation of the existing calculation method is analyzed, and a method to calculate luminous flux by vector ray tracing based on aperture stop constraint mode is introduced. The expressions of feature points coordinates and illuminated area of the first optical surface from abaxial ray under the control of aperture stop are presented through vector analysis and derivation. According to the condition and the law of Lambert radiator, from object space of lens, two kinds of lens image illumination analysis modes under conjugated condition are set up. For similar imaging system and non-similar imaging system with large field, the expressions of image illumination and relative illumination are derived respectively. A basic scheme to increase relative illumination during optical designing is proposed.

Pedestrian detection is one of the most active research topics in the fields of pattern recognition and machine learning. It has been widely used in intelligent monitoring, auxiliary driving and so on. Generating pedestrian detection proposals is an important work in the early period of pedestrian recognition and pedestrian tracking. Based on the static monitoring scene as well as the on-board monitoring scene under specific circumstances, a novel method to generate pedestrian detection proposals quickly (OL_GMPG) is proposed by using online Gaussian model. High detection rate can be achieved by generating fewer pedestrian detection proposals through the Gaussian model fitting. Both the positions where people appear most frequently and the scale information of corresponding targets can be obtained through the learning and updating processes of the Gaussian model. The information is beneficial to subsequent pedestrian recognition or pedestrian tracking.

In order to solve the distortion problem of camera imaging process in pose measurement, a novel camera calibration method is proposed. The method does not need high precision calibration reference, and only utilizes the mutual constraint relationship among the calibration targets to establish the constraint equation between camera intrinsic parameters and target characteristics, subsequently camera intrinsic parameters are solved linearly. Optimization of camera intrinsic parameters is made by nonlinear optimization method, thus, the camera calibration is accomplished. Simulation and experimental results show that the proposed algorithm is not sensitive to image noise. The measurement accuracy and reliability are effectively improved, and the precision can reach 0.03 pixel, which indicates that the algorithm has advantages of easy implementation, high measurement precision and reliable in the attitude measurement of the cooperative object.

A sea-sky-line detection algorithm based on the improved active contour model is proposed to detect the elliptical sea-sky-line of the panoramic sea image. The visual saliency map of the image is obtained by the full resolution algorithm, and then the position of the panoramic device area in the panoramic image is extracted to eliminate its adverse effect of device area interference on the sea-sky-line detection. According to the characteristic that the panoramic sea-sky-line is elliptical, a shape energy constraint function is constructed and added to the active contour model, so a new energy function is formed. The new energy function limits the shape of the active contour in the convergence process, and the contour shape is converged to the panoramic sea-sky-line successfully. Experimental results show that this algorithm is applicable for panoramic images under different shooting conditions and its detection accuracy reaches 96%. The universality and robustness of the proposed algorithm are excellent.

For practical demand of the localization of multiple random objects with large view filed, long distance and same features, a 3D coordinate measuring system is established based on the binocular stereo vision theory. To precisely position the multiple random objects with the same features, the multiple objects need matching correctly. An innovative method based on the Delaunay triangulation and affine constraint is proposed to achieve correct matching of the multiple objects with same features. The matching points on the background images are obtained with the affine scale-invariant feature transform (ASIFT) algorithm that has an anti-affine transformation. The Delaunay triangulation algorithm is used to generate triangular meshes by the seed points. The affine matrix of the triangular region is calculated by using vertexes of matched triangles. According to the distribution of object points in different matched triangles, the multiple objects with same features will be matched by the affine constraint. Experimental results show that the proposed method realizes the fast and efficient matching of multiple objects with same features. The time of object extraction and real-time matching is about 30 ms, which satisfies the requirement of 25 frame/s real-time processing for cameras. The proposed method solves the problem of matching of multiple objects with same features on the arc slope in large 3D space.

To improve heat flux density at the exit of the integrator of arc lamp heat flux calibration system, an approach is proposed. Firstly, the principles and design objectives of the system are briefly introduced. Secondly, the selection and location of xenon arc lamp are analyzed. Thirdly, according to the restriction relationship among the lamp, the ellipsoidal specular and the integrator, relevant parameters of the ellipsoidal specular and the integrator are designed and optimized. Finally, a new calibration system with all optimum indicators is obtained. In the new calibration system, the heat flux density at the exit of integrator increases by 33% when unevenness is less than 3%. The truncation diameter and the depth of the ellipsoidal specular decrease by 16% and 18% respectively. Under the same process conditions, the results can lead to a higher process accuracy of ellipsoidal specular.

The relationship for synchrotron radiation infrared beamline between the aberration of symmetric optical system formed by two toroidal mirrors with the same optical parameters and pantograph ratio of the toroidal mirrors is analyzed. Computation results show that toroidal mirror with 3∶1 compression ratio can optimize the infrared beamline transmittance of chemical vapor deposition (CVD) windows to 50% at the working wavelength of 500 μm on the Synchrotron Radiation Infrared beamline BL06B at Shanghai Synchrotron Radiation Facility. The ray trace results by the optical design software Zemax show that the aberrations of the symmetrical structure do not affect the aggregation performance of the infrared beamline. Synchrotron Radiation Workshop simulation results show that the photon flux obtained with a pair of three times compression ratio toroidal mirrors and a diameter of 15 mm CVD diamond window is equal to a pair of 1 time compression ratio toroidal mirrors and a diameter of 45 mm CVD diamond window, while the former carbon peak absorption is about 37% of the latter. The symmetric optical structure formed by two toroidal mirrors with 3 times compression ratio can be used to optimize the performance of the SRIR beamline in the far infrared wave band, while the performance in the near and middle infrared wave band are also take into account.

In order to realize the quantitative guidance for the focusing of dish concentrator mirror unit, it is essential to establish the unique quantitatively corresponding relationship between the mirror unit posture and the focal spot feature. We have presented the equivalent posture error by combining rotation and translation movement of the mirror unit, and the focal spot flux density distribution model under the posture error condition is established based on the ray tracing method. The concentration ratio threshold is applied to extracting the boundary characteristics of the focal spot, and the least-squares method is used for elliptical fitting of the boundary characteristics which represents the distribution characteristics of the focal spot. The factors influencing the focal spot characteristics are analyzed, including the direct normal solar irradiation, concentrator ratio threshold, and mirror unit posture error. The results show that the ellipse geometry of the focal spot under different mirror unit posture error conditions can be obviously distinguished, and it is feasible for the mirror unit posture inversion, which provides reference for the construction of the subsequent mirror unit focusing system.

The computed tomography technique is employed to reconstruct the structure of Ni foam, and the Monte Carlo method in combination with the octree algorithm to model the pore-scale radiative transfer of Ni foam. The accelerating effect of the octree algorithm on the radiative transfer is analyzed. The results indicate that the maximum relative error of the calculation value of radiative property between with and without the octree algorithm is less than 1‰. Within the range of optimal spatial depth, the larger the spatial depth and the more the model element is, the more obvious the accelerating effect in computation is.

The accuracy of satellite attitude data is an important factor restricting the geometric positioning accuracy of high-resolution images. For the current problems that the accuracy of satellite attitude data processing is not high and data assessment is difficult, an algorithm of satellite attitude data ground processing is proposed based on bilateral filtering and overall weighted smoothing to achieve high-accuracy processing for attitude data. Furthermore, the numbers are digital orthophoto map and digital elevation model reference data of geometric calibration field is used for accuracy assessment. By using high-resolution optical satellite of Yaogan-24 launched in November 2014 as an example, the processing results illustrate that the proposed method is robust and feasible. The relative accuracy of attitude data can reach 0.8″, and the positioning accuracy of panchromatic camera geometric correction image can increase to 15 m via using the refinement attitude data.

To meet the detection accuracy requirement of the polarization remote sensing system, a polarization detection system is used, whose focal plane is divided by multi-linear array polarizers. The effect of the extinction ratio on the polarization detection accuracy is analyzed, and a polarization radiation transfer model is constructed. The structure of the divided focal plane polarization instrument is introduced. By combining the micro-polarizer processing technologies both in China and abroad, a detection method is chosen, which uses the multi-linear micro-polarizers to replace the micro-polarizer mosaic array. The influence of the extinction ratio of the metal wire grating micro-polarizer on the detection accuracy is discussed. The polarization transfer matrices of the optical system and the non-ideal polarizer are derived. According to the polarization radiation transfer theory, a calibration model for the polarization detection system is constructed, and a corresponding parameter calibration scheme based on the calibration model is developed, which provides a theoretical basis for the polarizing radiation calibration in laboratory. The simulation and experimental results show that the detection accuracy of the system influenced by equipment stability is 0.5%, which can meet the accuracy requirement of the polarization detection.

Based on new calibration technique of photon correlation, a prototype of self-calibration radiation reference source (SRRS) is designed. This prototype combines the self-calibration and observation target function. The precision of observation for target can be guaranteed by accurate measurement of detection efficiency in observation channel. A two-channel self-calibration spectral radiation prototype is established, and the photoelectric detection efficiency of observation channel is measured through the principle of correlated photon calibration. The measurement uncertainty of 0.35% for detection efficiency is obtained. SRRS can realize self-calibration for photoelectric detection efficiency of observation channel. Transmittance changes of any optical element in the observation channel don′t affect the measurement accuracy of radiance of the objectives. An attenuator is inserted into the observation channel to simulate the sight path photoelectric detection efficiency changes, so as to verify the sensitivity of calibration spectra from the radiation source on the decay of the observation channel. By measuring the photo count or coincidence count before and after inserting the photon attenuation, the actual transmittance of 20.12% of the attenuator is calculated, and it is in accordance with the change rate (20.11%) of the photoelectric detection efficiency for observation channel before and after inserting the attenuator. The relative deviation between the two is less than 0.049%. Experimental results show that the radiation spectrum from the self-calibration mechanism can accurately monitor the decay of observation channel photoelectric detection efficiency. Rationality and feasibility of the SRRS design are preliminarily verified, which provides the technical basis for subsequent multi-channel self-calibration spectral radiation prototype development and calibration of radiation.

In order to further realize the miniaturization of the Fourier transform infrared spectrometer, a spatial light modulator and a point detector are introduced in the Fourier transform infrared spectrometer which is based on multistep micro-mirror. The phase of incident optical field is modulated by the multistep micro-mirror, and the distributed measurement is conducted for each interference order using the spatial light modulator. The two multistep micro-mirrors are regarded as two phase diffraction screens, and the spatial light modulator is regarded as an amplitude diffraction screen. The interaction between optical wave and each diffraction screen is analyzed. It is found that the interference optical field is modulated by the spatial light modulator and the diffraction optical field at the multistep micro-mirror margin. The incident optical field is cut off by the multistep micro-mirror margin, which results in the diffraction effect. In order to inhibit the influence of diffraction effect on the system, a method which extends the step order of the multistep micro-mirror is proposed. By means of enlarging the interference area, the influence of the marginal diffraction effect on the internal effective interference order can be avoided. The results indicate that this method can eliminate distortion of the interferogram sequence and achieve signal spectrum recovery effectively.