A method of near-field trapping high and low refractive index Rayleigh particles was proposed using a binary phase Subwavelength Fresnel Zone Plate (SFZP) illuminated by the double-ring-shaped vortex beam. Based on the angular spectrum representation, the distribution of SFZP′s diffraction field was calculated. Bright and dark spots can be generated in the near field of the SFZP by changing the truncation parameter (β) and the vortex angle (δ) of the incident beam. Numerical results show that the SFZP can generate a subwavelength three-dimensional (3D) bright spot in the near-field region when β=1.09 and δ=0. The tiny bright spot can be used to stably trap a gold particle with radius 19 nm, whose refractive index is higher than that of the ambient medium. The axial and transverse trap distances are respective 0.4921λ and 0.2844λ. When β=1.45 and δ=0.414π, a 3D dark spot surrounded by a light shell can be formed in the near-field region. An air bubble with radius 30 nm is stably trapped at the center of this subwavelength dark spot. The refractive index of the air bubble is lower than the ambient medium. The axial and transverse trap distances are 0.62λ and 0.3081λ. The trap distance obtained under two conditions is less than that in the conventional far-field trap system. The single trap system can be used to accurately trap two types of Rayleigh particles with different refractive indices.

Based on the difference between nomal grating and immersion grating,the immersion grating equation was deduced.Immersion medium absorption was studied as the reason of the single slit diffraction and the change of the multiple beam interference intensity distribution.The correction factors of single slit diffraction and multiple beam interference were concluded,and the intensity distribution formula considering the medium absorption was deduced.The formula is more general and the single slit diffraction intensity distribution formula,the multi-slit diffraction intensity distribution formula and the parallel-plate multiple beam interference intensity distribution formula are special cases of the correction formula.

The change rule of phase-modulation beat-frequency-signal following signal light frequency was analyzed theoretically. It is found that the frequency spectrum of phase-modulation beat-frequency-signal phase is composed of two monotone edges separated from each other in domain. The results indicate that the beat-frequency-signal phase can be used to measure Doppler shift, and its Doppler shift measurement range is two times of Fabry-Perot interferometer edge technique if outgoing laser work-point is locked using beat-frequency-signal amplitude. Theoretical analysis of beat-frequency-signal amplitude and phase extraction methods shows that the measurement method based on beat-frequency-signal phase does not need signal light energy detection, and has simpler structure and less one outside noise entering channel than Fabry-Perot interferometer edge technique. For quantitative research and parameters optimization of this Doppler shift measurement method, its measurement error formula was deduced by using the error combination principle and computer simulation. The experimental system is set up based on the measurement principle. The output light of frequency tunable fiber laser simulates Doppler frequency shift signal light to be measured. The measurement results of frequency-discrimination parameter and its error distribution curves are agreed with the theoretical results well.

The phase unwrapping method based on the polar coordinate to get the alignment offset was proposed for the wrapped phase generated after the single closed interference fringe phase extraction in alignment of nanolithography. The phase distribution of the fringe pattern occurs in the relative movement between two circular gratings was transformed from rectangular coordinates system to polar coordinates system firstly; then the relationship between the alignment offset and the phase parameter was analysis in polar coordinates system; the initial phase amplitude and phase delay in different radial radius were got to acquire the alignment offset finally. The feasibility of the method was verified by numerical simulation and experiment and the comparisons of the tradition least squares method and path tracking method are given. The results show that the wrapped phase can be unwrapped for the alignment with high precision in tens of nanometers through the method with good adaptability.

As the conventional angular measuring system which uses rotary encoders has the shortcomings of low resolution, large quantization noise and low angular velocity accuracy, a sensor fusion angle measurement method based on fiber optic gyroscope and rotary encoder was proposed. First, the encoder angle signal and the fiber optic gyro rate integration value were subtracted in a sliding window, and the rate drift of fiber optic gyroscope was estimated utilize least square method from the deviation signal. Secondly, the angle was estimated using the compensated angular velocity signal and the encoder signal through a certain combination algorithm. Finally, mathematical simulation and experimental verification were conducted for the proposed method. The results show that the simulation value and experimental value of angle measurement accuracy are improved from 1.2″ and 1.1″ to 0.17″ and 0.76″, respectively. The angular velocity measurement accuracy are also improved from 0.002°·s－1 to 0.001°·s－1. The proposed methed effectively improves the angle and angular velocity measurement accuracy, while avoiding the rate drift problem of fiber optic gyroscope.

In order to measure the three-dimensional shape of a non-cooperative target in a close distance in the missions for space targets operations, a line structured-light three-dimensional shape measurement system based on laser triangulation with auto-synchronous scanners was designed. The principle and the configuration of the system were presented and the line structured-light scanners system model was derived. The prototype system was set up and calibrated with a chessboard. The groove board and Tiangong-1 scale model were measured. The measurement results show that the precision of the spatial coordinates measurement is better than 1 mm, the precision of Z coordinates measurement is 0.18 mm, and the average errors of the distance between the measuring points and the fitted plane are 0.31 mm at the distance of 1 m. The system can simplify the scanner and reduce the weight and power consumption, and can be used for the rapid three-dimensional shape measurement in the space missions.

A method based on weighted least squares surface fitting was studied, which was used for astronomical observation space target. This method can be used in celestial positioning of high-precision and large data quantity, and it is also very simple. Through observing the real sky, the star maps continuously were calculated. The results show that the fitting mean square errors are all less than 4″ in the direction of ascension and declination. The positioning accuracy in the direction of declination is better than that of ascension, the max positioning error of the observed stars are 5.13″and 1.74″ in the direction of ascension and declination . It’s demonstrated that the effects of star centroid errors are reduced, and the match up errors are also removed. The utilization of observed data and the precision of celestial positioning is improved. The method is well suited for application.

By using the linear approximation method, the intensity correlation function C(t) of loss model laser system with a biased amplitude modulation was calculated. The different forms (irregularly periodic increasing, decreasing and so on) were obtained in the evolution of the intensity correlation function C(t) with the time t. The results indicate that: in the case of a0=0.1, the flat irregularly periodic oscillation is shown; the period of irregularly periodic oscillation is adjusted by the low frequency Ω of modulation signal; the initial value and the period of C(t) can be changed by the intensity of quantum noise Q and the high frequency ω of carrier signal.

The laser beam transmitting in the rain would be scattered and attenuated by the raindrops, so that the laser ranging system will be false alert and invalidation. Based on geometric optics theory, the raindrop backscattering model was founded, and the backscattering coefficients of different rainfall rates were calculated. Combined with engineering application, the signal-to-noise ratio at different rainfall rates and transmission distances were calculated, and the affect of raindrop backscattering to the system SNR is analyzed. The calculation results indicate that the system SNR is decreasing with the increasing of the rainfall rates and the attenuation rate is up to 11% in the heavy rain. And at the same rainfall rate, the attenuation rate of SNR is up to 46% or more when the distance increases from10 m to 15 m. The rainfall rate and distance are the important factors to affect the system signal-to-noise ratio, so the study on backscattering characteristics has important instruction for the design and optimization of high anti-interfering performance laser ranging system.

Femtosecond laser double-pulse has important application value on the study of ultra-fast transient process area. How to realize the high accuracy of femtosecond laser pulse real-time measurement is particularly important. This paper presents a method on autocorrelation of femtosecond laser double-pulse measurement. It contains the measurement techniques of pulse interval, pulse width and the intensity ratio. Autocorrelator was used in the experiment to get the autocorrelation curve of the femtosecond laser double-pulse. The femtosecond laser double-pulse were generated by the birefringent crystal. Relying on the autocorrelation curve, the pulse interval, pulse width and the intensity ratio were got by non-linear fitting method. Contrasted the traditional cross-correlation measurement, the autocorrelation method overcome the uncertainty of the independent pulse impact on accuracy. It makes the measuring precision could be improved by more than 48% on average.

A structure of artificial compound eye was put forward which was centered on high-resolution and small field of view sub-eye lens and has many large FOV and low-resolution sub-eye lens on the curved surface by array configuration. Based on the principle that object field should be seamless stitching and reduce overlap regions, the mathematical relationship between the field angles of sub-eye lens in the X direction and Y direction and the one of the whole compound eye system was analyzed, the mathematical model about the period of marginal array sub-eye lens was deduced. And then, the arrangement criterion of the sub-eye lens array on curved surface was confirmed. The spherical surface part was designed by the arrangement criterion, an alignment method with using of the auto-collimating theodolite and the digital picture processing technique was proposed. The central sub-eye lens and marginal first array sub-eye lens was assembled in the course of adjustment. The results of image data acquisition show that overlap regions of objective field are the same as the theory design, which confirms the arrangement of sub-eye lens is reasonable and the alignment is feasible.

In order to satisfy the optical imaging system of ultraviolet (UV) focal plane arrays with wide spectrum and large field of view design demands, all-reflective Schmidt system was studied. Based on wavefront analysis at the center of curvature of a spherical mirror, the equations of refractive and reflective Schmidt correctors were derived. For avoiding central obscuration, the off-axis all-reflective Schmidt system was established which was characterized by the 240 nm~950 nm wide spectrum and ±5°field of view , the design results show that when λ=0.24 μm, u′m=5°, Δf≤0.031 5 mm, the detection is in the depth of focus and the image quality reaches the diffraction limit. The optical design method for Schmidt system can be applied to the UV imaging system with high resolution and wide spectrum.

For supplying space object detection and recognition with reference data,space object optical scattering characteristics model is established using TracePro.Combining with structure,material,background and orbit,the optical scattering characteristics of the space-based infrared system is simulated by creating solid model,defining material,defining light source and tracing rays in TracePro.The simulation results show that the object spectral irradiance is coincident with that of the sun.The object equivalent reflectivity is coincident with that of the GaAs in specular direction.As the object rotates,the object equivalent reflectivity turns to agree with that of the cladding material,and then keeps stable.The research could provide reference idea for the next work.

The Segmented Telescope is the most effective way to build a giant telescope. 10 meter and larger telescopes are needed to be carried out further for our country. The analytical expression of the Point Spread Function (PSF) for 10 meter Segmented telescope was derived, based on optical diffraction theory. A numerical simulation model was established. The Gaps of Sub-segmented mirrors and Piston error, which affect far-field image quality, were analyzed. Both theoretical analysis and simulation results demonstrated the following: PSF of Segmented telescope can be obtained by multiply coherence function(GF) of Sub-segmented mirrors′ center position with single Sub-segmented mirror′s PSF. Gaps between Sub-segmented mirrors could blur diffraction spot and decrease the peak energy. Piston error of the Sub-segmented mirror could affect the GF of the PSF seriously. Thereby, Strehl Ratio of the system could be decreased and the frequency of GF is not changed. Tip-Tilt error of Sub-segmented mirrors would cause frequency shift in every PSFs and the whole PSF could be affected and the Strehl Ratio would be decreased.

In order to solve the problem that the real solar angle and true irradiance (one solar constant) can not be simulated by the existing solar simulator at the same time, a new type of solar simulator optical system was designed. The design method of the optical system of the condenser was described, and the optimization technique of optical integrator and defocusing effect of projector lens were discussed. Using Zemax, optical integrator was designed by sequence and non-sequence, and the field diaphragm and the collimating lens system were also designed. The optical system was simulated with LightTools software, and the results show that 32′ of real solar angle and a constant solar irradiance can be achieved by the solar simulator, irradiation non uniformity in Φ100 mm range is less than ±1.6% and in Φ(100~300) mm is less than ±3.8%.

To overcome the shortness of traditional algorithms relying on the point source assumption,a freeform surface optimization method for the extended source was proposed based on the genetic algorithm.The optimal objects involve the radiation distribution function,the offset of origin and the size factor of receiver about the virtual point source.For each individual the reflector can be calculated numerically by solving the partial differential equations established according to the energy conservation law and Snell′s law corresponding to the set of virtual parameters.The individual fitness concerning the uniformity of the object region and the transmission efficiency was obtained according to the simulation results with an actual extended source.The selection,crossover and mutation operations are implemented until the optimization results can meet the requirements.To verify the effectiveness of the proposed method,a uniform lighting system with cone angle of 10° was designed.The contrast experiments are carried out in Trace/Pro with a disc lambertian source with the size of 30 mm in diameter.The light tracing experiments show that the uniformity of the object region increases from 58.3% to 93.5%,and the transmission efficiency increases from 61.8% to 72.9%.Meanwhile,the optical quality has quite good stability at varying distances.The experimental results demonstrate that the method can achieve the adjustment of the spatial distribution of the extended source radiation which has significant guidance for the design of extended source system.

An auto focusing method based on auto focusing window selection was presented according to the imaging principle and characteristics of fundus images.The preliminary focusing window is extracted through the focusing window selection algorithm based on local entropy with improved threshold.The final window is located through multi-directional stepping algorithm.The image sharpness evaluation function combined with the characteristics of local contrast sharpness evaluation function and gradient vector square function was presented according to low contrast fundus images.Experimental results show that the presented auto focusing window selection algorithm ensure the stability and accuracy for the focusing window,and the image sharpness evaluation function has better sensitiveness for low contrast fundus images.

The typical two-step phase-shifting algorithm cannot get rid of the problem in phase unwrapping processing, which is caused by the uneven distribution of intensity and the uneven reflectivity of objects. Aiming at the problem, a intensity formula, reflecting the reflectivity of the objects, is adopted, based on the analysis of 90° phase shift. The intensity data was operated directly. Then, according to the triangle theory, a algorithm was presented to get the half angle of wrapped phase. At last, three-dimensional shape information of the tested object was decoded, according to the relationship between height and difference of phase. This method avoids the errors caused by the method used to get the maximum or minimum value. The results of the proposed method are compared with those of the typical four-step phase-shifting algorithm and the two-step phase-shifting algorithm. When the surrounding intensity can be ignored or weak, its error is ±0.2 mm. It is better than resutls of typical two-step phase-shifting algorithm, close to results of accepted low-error four-step phase-shifting algorithm.

A fast image defogging algorithm based on edge-maximum filter was proposed to address halo effect and color distortion caused by the existing defogging methods. Firstly, an edge-maximum filter was used to recover the undervalued dark pixels obtained by edge detection, which was to receive an accurate transmission map and eliminate the halo effect. Then in order to gain a high contrast dehazing image, all the dark pixels were multiplied by a scaling factor to improve the dynamic ranges of the transmission. Finally, two brightness thresholds and one flat threshold were set to eliminate the influence of high light objects in the image and obtain a more accurate airlight, which keeps a high color fidelity in the dehazing image. The simulation results show that the proposed method, compared with other algorithms, could eliminate the halo effect and achieve the dehazing image with high contrast and high color fidelity, especially for the images containing high light objects or rich details. Meanwhile, the computational speed is also improved.

Vertical graphene edge is easy to adsorb gas molecules which affects the stability of field emission. The graphene was transferred to insulation wall structure to get the graphene-angle. The insulation wall structure is made on silicon substrate by inductively coupled plasma etching and the method of wet etching, field emission test was made with graphene-angle as field emission tips, and the field emission characteristics of the graphene-angle and the influence of conductive flow on the field emission were studied. The results show that field emission open field strength of graphene-angle is 9.6 V/μm. Under the anode voltage 2 000 V, when the bias voltage applied on the both sides of the graphene-angle increases from 0 V to 10 V, the field emission current increases from 4.5 μA to 15 μA.

In order to obtain the strongest yellow luminescence intensity of the novel Bi2ZnB2O7: Y3+/Dy3+ phosphor, uniform design and quadratic general rotary unitized design were combined to optimize Y3+/ Dy3+ ions doping concentrations, the result shows that the optimum doping concentrations of Y3+/ Dy3+ were 4.498 mol% and 6.001 mol%, respectively. High temperature solid state method was applied to synthesize the optimal sample, and the crystal structure and luminescent properties were investigated. The emission spectra of the samples under 452 nm excitation were observed, where the blue emission band was at around 460~500 nm, the yellow emission was at around 550~610 nm and the weaker peak of the red emission is at around 650~700 nm. They were corresponding to the emissions from the 4F9/2 excited state to the 6H15/2, 6H13/2 and 6H11/2 ground states, respectively. The result indicates that the Dy3+ ions were located at a non-centrosymmetric site in the host lattice. Besides, the luminescence decay curve illustrated that the fluorescence lifetime of Dy3+ was 0.427 ms. It was found from the comparison between the optimized and the single-doped samples with the same Dy3+ concentration that Y3+-introduction could improve the emission intensity of the studied phosphor in a certain degree.

In order to explore the relationship restoring Casimir force between the doped silicon slab and electromagnetic metamaterials with related parameters,basing on the generalization of the Lifshitz theory and Green function for Maxwell force tensor,the Casimir force between the doped silicon slab and metamaterials were calculated.The results show that the magnitude and the direction of the Casimir force can be tunable by varying the doping level,the thickness of doped silicon slab,and filling factor of metamaterials.Consequently,the force can be controlled by those factors.

Based on the influence of lithium content in some optical materials to the structure stability and optical proterties,the structure stablility and vibration spectroscopy of carbon-doped clusters LinC(n=1~9) were investigated with density functional theory at the B3LYP/6-31G(d) level.The computed results shown that the structure were three dimension(n>3) structure for LinC except for Li2C and the carbon atom was seen to be trapped in a Li cage.Especially,the electron ground state was found to be a low state for LinC cluster,singlet for n is even while doublet for n is odd.A strong even-odd alternation in the cluster stability appeared in the incremental binding energy,with their n-even numbers being much more stable than the adjacent odd-numbered ones.These parity effects also appeared in the second difference in energy and the gap between HOMO-LUMO.In addition,the dominant channel was losing a Li particle for LinC clusters by analyzing the fragmentation energies.The spectroscopy range of LinC clusters located in fingering area.The vibration frequency of LinC clusters decreased with the increasing of the numbers of Lithium atoms.Moreover,the difference between the lowest and the highest vibration frequency shown maxmium as the number of lithium atoms was odd while it shown minimum as the number of lithium atoms was even.

In order to research nonlinear absorption effect of pulse laser irradiation for GaAs,a physical model of Gaussian distribution pulse laser irradiation for semiconductor material was established by software COMSOL Multiphysics. The thermal effects of semiconductor material GaAs was analyzed under irradiation of nanosecond pulse laser with wavelength of 1064nm. The temperature distribution along radial direction and longitudinal direction of semiconductor material GaAs was calculated under irradiation of nanosecond pulse laser with different power density by means of solving the thermal conduction equations. The contribution of one-photon absorption, two-photon absorption and free carrier absorption to temperature of the irradiated material was discussed. The calculation results show that when the pulse laser power density is above 1010W/cm2, Free Carrier Absorption played a leading role and is more than that of One-Photon Absorption of material. When the pulse laser power destiny is below 108 W/cm2, the temperature contribution of two kinds of nonlinear absorption of materials could be ignored. The result is basically consistent with relevant experiments, which shows that physical model constructed is scientific.

Vapor etching was used to etch diamond wire sawn multicrystalline silicon wafers. The vapor was produced from 2 g silicon wafer adding into HF-HNO3-H2O acid mixture solution (400 mL, in the volume ratio of 6: 3: 1) to reaction at room temperature. Diamond wire sawn multicrystalline silicon wafers were etched in vapor. Etching for 4 min, saw marks can be removed and honeycomb etched pits were densely covered with silicon wafer surface. The reflectivity of silicon wafer decreases remarkablely by using the vapor etching methods. The reflectivity of the silicon wafers by vapor etching is low to 19.51%. The micro-roughness of diamond wire sawn mulicrystalline silicon wafers etched with vapor method is actually about 20% higher than that of etching with traditional acid mixture solution method.

In order to efficiently extract the first and second harmonic signals from the differential signal in infrared gas detection based on tunable laser absorption spectroscopy, an orthogonal phase lock-in amplifier was developed. According to the principle of orthogonal lock-in amplifier and harmonic detection, the simulative experiment system based on Simulink platform was set up, and its functions were simulated and verified. The hardware system is designed and developed by adopting a digital signal processor as its core controller, which is mainly composed of a 90° phase shifter, two analog multiplier, two low pass filter, a differential signal amplifier and an AD converter. In experiment, firstly, by using standard sine-wave signals with tunable amplitudes as the signals to be measured, the amplitudes of the output signals from the fabricated lock-in amplifier and the standard amplitudes are both tested and compared. Good linear relationship is found between them, the linear fitting degree is as high as 0.999 94, and the maximum error is less than 4%. Secondly, using the simulated differential signal with gas absorption as the signal to be measured, and by using fundamental square wave signal and frequency-doubled square wave signals as reference signals, both first and second harmonic signal are extracted. Because the second harmonic signal is too weak and easy to be polluted by noises, its detection error is less than 5%, and that of the first harmonic signal is less than 3.5%. The proposed system has good applicative prospects in infrared gas detection due to good stability and high price ratio.

Assuming that the photocurrent is much larger than the diode reverse saturation current,shunt resistance is infinite and diode reverse saturation current is independent of light intensity,a performance prediction model of photovoltaic module under different operating conditions was proposed and a simulation system was built by using Matlab/Simulink programs.Through the comparison between computer simulations and experimental data for mono/poly crystalline silicon photovoltaic modules,it showed that the proposed model can accurately predict the photovoltaic modules output characteristics at different light intensities and temperatures,and the relative prediction error precisions were all below 6%.The results also reveal that temperature change has a greater impact on modules performance prediction than the light intensity,and it is harder to predict module performance of polycrystalline silicon than that of mono crystalline silicon.Moreover,the prediction results of photovoltaic modules performance in natural environment showed that the output characteristics of the modules are mainly determined by light intensity rather than by temperature.it is found that the output voltage of the modules should be varied when conditions of light intensities and temperatures change,in order to achieve the maximum output power.