To improve the accuracy of the visibility measurement and the evaluation of the measurement results, one method of changing baseline lengths visibility measurement is proposed. The least squares method is used to reduce the impact of errors of the position of the receiver and transmittance measurement on extinction coefficient. This can improve the measurement accuracy of the extinction coefficient. To verify the effectiveness of the method and evaluate the performance of the method under different visibility conditions, one mobile measuring platform is designed. Meanwhile a continuous atmospheric environment changing from high to low visibility is simulated in the atmospheric simulation chamber. In the simulation chamber, using the mobile platform, multi-point and multiple times measurements method is used to measure the extinction coefficient under different visibility conditions. The results show that this method has a high measurement stability and consistency under different visibility conditions. In the fitting process, coefficient of determination R2 increases with the visibility decreasing. When visibility is more than 3000 m, coefficient of determination can reach 0.9. Coefficient of determination can reach 0.99 in lower visibility. The unit weight variance is between 10-4 and 10-2 regardless of high or low visibility, this indicates the method has very smaller discrete and higher accuracy, which makes it potential to be used as the calibration of instrument and calibration of reference.

For adaptive optics with curvature sensor, a close- loop wavefront correction technique based on eigenfunctions of laplacian is introduced, and the wavefront correction error is analyzed theoretically. A numerical simulation model of 61 element adaptive optics is setup. The simulations of atmospheric turbulence wavefront aberration correction are carried out. The numerical simulation results are in agreement with the theoretical analysis results, which show that the close-loop correction accuracy is lower when the amount of eigenfunctions modes is less or more because of the mode coupling increment. Finally, by analyzing the relationship between the mode amount and the condition number of retrieval matrix, a simple and practical method is proposed to choose the proper mode amount.

The influence of diffraction of subwavelength relief grating on antireflection and transmission performance is investigated. Theoretical analysis shows that, for achieving both effects of antireflection and transmission enhancement, the period of grating must be small enough to eliminate the lateral waveguide loss caused by diffraction. In order to achieve antireflection effect only, the lateral waveguide caused by grating diffraction can be full used to reduce the reflectivity. Small grating period is not required at this point. The effects of period, duty cycle and groove depth of one dimensional relief gratings on reflectivity are investigated with the method of rigorous coupled-wave theory. A one-dimensional relief grating with period of 290 nm is fabricated by two-beam interference method. Experimental results show that it has significant antireflection effect in the whole visible light wave band and wide angular range, but this effect is only reflected in the non-diffraction region. The fabrication difficulty can be reduced greatly by choosing a reasonable grating periods according to the applications, which plays a positive role in using subwavelength gratings more economically.

Orthogonal frequency division multiplexing based on coherent detection is considered as one of significant solutions for future high-speed optical communication technology. However, because the structure of coherent optical detection system is complex and hard to implement, the subcarrier heterodyne detection technology is utilized to detect the subcarrier orthogonal frequency division multiplexed optical signal. The transmission system of atmospheric turbulence channel is established. The close form expressions for subcarrier average carrier-tonoise ratio (CNR) and average bit error rate (BER) are derived. The effects of opticallocal oscillator power and modulation index on average bit error rate of the system are numerically analyzed and verified by simulation experiment. The results show that subcarrier heterodyne detection is able to further improve the average CNR and therefore to obtain a better BER performance of the system compared to direct detection. When the order of the received optical is microwatts and the optical local oscillator power is close to -11 dBm, the best value of average CNR would be achieved. When the local oscillator power is larger than -11 dBm, the average CNR gradually reduces and the average bit error rate raises with the increase of optical local oscillator power. When the received optical power is larger than - 17 dBm and the average BER is greater than 10- 5, the reliability of wireless optical communication system under weak turbulence would be ensured.

A temporal signal measurement equipment for current 100 Gb/s fiber optic transmission, based on the linear optical sampling technique, is proposed and experimentally demonstrated. In the self-developed prototype, a passively mode-locked fiber laser is used as optical sampling source with a pulsewidth of 2 ps and repetition frequency of 96.25 MHz. Then, the polarization division multiplexing quadrature phaseshift keying (PDM-QPSK) signal under test is optically mixed with the sampling pulse before phase and polarization diversity detection. With the help of four-channel 400 MHz balanced photodetectors, four-channel analog signals are transmitted to the mainframe, for the purpose of digital signal processing and result display. By optimizing the design, pulse power, central wavelength, repetition frequency of passively mode-locked fiber laser can be output stably. Furthermore, the performance comparison with the counterpart from Agilent modulation format analyzer (N4391A) is carried out, and it’s verified that the prototype has almost the same capability for on-site measurement.

Based on the requirement of the wavelength division multiplex communication, an optical antenna is designed. Compared with the similar spectral communication system, the antenna has the advantages of large number of channels, large optical gain, high efficiency, etc. After theoretical analysis, the structure of double cylinder mirror with reflecting grating is proposed, which can not only maintain high spectral resolution at spectral dimension and improve the system’s communication rate, but also decrease the spot size at spatial dimension and increase the optical gain of the system. The simulation results show that the antenna can receive eight kinds of different single spectrum signals efficiently.The field of view reaches 18°×0.4°, the optical gain is 12.6, the optical signal-to-noise ratio achieves 48.28 dB and the size of the optical antenna is 9 cm×12 cm. At last, a prototype based on the design is produced, and the experiments show that the antenna can receive the multi-spectrum signal efficiently and the signal noise rate(SNR) is high enough for wavelength division multiplexing (WDM) optical communication.

An optical time-division multiplexing (OTDM) technique based on the Faraday rotator and three port circulator is designed. The polarizations of the optical pulse exported from the OTDM system are all the same, which have greatly increased the polarize stability. The effect of the adjusted errors on the intensity and time are analyzed with frequency spectrum. The results indicate that the power density varies only on the frequencies which are multiples of the basic frequency. A spectral analyzer is used to achieve a real-time measurement on the errors of intensity and time. The effective-number-of-bits of the five degree OTDM is 6.15 bit.

Self-interference incoherent digital holography (SIDH) retrieves the object information from the digital hologram illuminated by the incoherent light. However, the reconstructed image according to different sections will be disturbed by the out-of-focus sectional image by employing the traditional numerical reconstruction method. Therefore, a numerical reconstruction method for SIDH by employing compressive sensing (CS) is proposed to achieve the reconstruction of three-dimensional (3D) sectional image.Firstly, according to CS, the sensing operator is built up based on the physical mechanism of SIDH. And then,the recovery algorithm is employed for the image restoration. Numerical simulation and experimental research on SIDH employing several LEDs at different positions are performed to demonstrate the feasibility and validity of the method. In addition, the relationship of the reconstructed distance according to different sectional images and the experimental parameters is discussed. The analysis result shows that different sectional images can be reconstructed with the out-of-focus section information inhibited.

In the image deconvolution of digital confocal microscopy system, the selection of spatial size of three dimensional point spread function (3D-PSF) is closely related to the effect of image restoration. Based on the principle of three- dimensional microscopic imaging and 3D- PSF model, the relationship between the energy distribution and the size of 3D-PSF is analyzed, and a 3D-PSF size selection method is proposed and realized, which uses the restoration efficiency - energy curve inflection point for energy threshold determination. The acquisition of image and the generation of 3D-PSF of bio-optical microscope objective of three kinds of numerical aperture or magnification are simulated, and the deconvolution restoration results of three-dimensional simulated cell images by using the 3D-PSFs with different energy are obtained. The experimental results show the effectiveness and feasibility of the proposed method, and provide a basis for automatic selection of 3D-PSF for the three-dimensional microscopic image deconvolution.

The image quality of the traditional Offner spectrometer may be unsatisfied when large dispersion is needed. Furthermore, severe ray obstruction may occur when relative aperture is not small enough. Therefore, an off-plane Offner spectrometer is suggested based on Rowland condition in this paper. An analytical design approach of an imaging spectrometer based on off- plane Offner configuration is presented. Astigmatism and coma are corrected in the design without ray obstruction. An imaging spectrometer is designed using the configuration with a spectral range from 350 nm to 1000 nm. The size of the spectral image is 12.6 mm. The modulation transfer functions in total fields of view and the whole spectral range are more than 0.78. The root mean square (RMS) spot radiuses are smaller than 4 μm. Meanwhile, the smile and keystone of the system are both better than 1% of a pixel size. Finally, a contrast between the off-plane Offner spectrometer and the in-plane configuration is performed. The result demonstrates that the off-plane Offner spectrometer has a better image quality for high spectral resolution if a shot entrance slit is allowed. There is also an advantage in eliminating the smile and keystone. The configuration can be applied to imaging spectrometers with small dimension and high spectral resolution.

Chirped pulse spectral interferometry is a commonly used continuous and high time-resolved diagnostic instrument, however, its applications in the fields of ultrafast and large timescales physics are constrained by the relationship between time resolution and test range. Utilizing linearly-chirped pulse series and a recording system of a spectrometer coupled streak camera, a scanning spectrum laser interferometer is designed. To demonstrate the feasibility, principle of the interferometer is studied theoretically and numerically. It is concluded that the scanning spectrum laser interferometer could measure phase perturbation signal accurately, and possesses the same time resolution and several times test range compared to chirped pulse spectral interferometry. Additionally, in the recording system, the influence of sampling intervals on the measurement results of the scanning spectrum laser interferometer is numerically analyzed. The results show that the influence could be ignored while raw data are clean, but if noise is contained, the measurement errors would increase gradually with the sampling intervals decreasing.

Surface shape measure of large aperture mirror components existing problems of high cost and strict environmental requirements. In this paper, based on the sub aperture stitching detection technology of S-H wavefront sensor, the stitching algorithm is improved, and the mixed stitching algorithm is proposed, which can effectively reduce the error caused by the sub-aperture stitching. With auto-collimation wave-front detection system and high precision two-dimensional scanning system, the reflective surface shape of large aperture reflector is detected by surface stitching. The experimental results show that the measurement error of the device is approximately 0.072 λ, which meets the requirements of the process of the large aperture mirror assembly from the high power solid laser.

The traditional linear CCD measurement method is only suitable for static image acquisition or displacement measurement at low speed. On the basis of the CCD dynamic error analysis in the process of dynamic measurement, a drive timing delay method which is synchronous measured by multiple CCD is proposed. This method uses multiple linear CCD arranged from beginning to end in a space and straggles with each other in time to realize multiple displacement values measurement, so as to improve the dynamic measurement range of linear CCD. To verify the validity of the scheme, a timing delay angular sensor is designed by a circular array which is constituted by five linear CCD sensors of the same tape, and the construction of the corresponding experimental system is completed. By measuring compare with high precision circular grating in the different rotational speeds, with the increase of speed, the timing delay measurement method of dynamic characteristics is obviously superior to the traditional measuring method. The results indicate that the level of dynamic error of the timing delay method in 30 r/min is equal to the traditional method in 10 r/min. It concludes that the feasibility of linear CCD dynamic characteristics improvement is verified with the timing delay measurement method.

A novel three-dimensional (3D) shape measuring method based on phase measuring deflectometry (PMD) is presented, which can be used to measure the aspheric mirror during the stages of fine grinding and the beginning of polish. The proposed method measures the absolute height and slope of the specular surface with incidence ray, camera pinhole and dummy assistant surfaces. During the measurement, a camera with an external stop is used to realize pinhole camera model. The external stop represents the position of the camera and the incidence ray corresponding to the pixels of the camera can be obtained by moving LCD screen once. The procedure of the test is simple and the result is believable because it has no restrict requirements for the experimental devices and no need of other auxiliary devices. What′s more, this method measures the specular surface with dummy auxiliary surfaces instead of the intersection of the incidence ray and the camera ray. So there is no need to calibrate the camera ray. This method can be used to test the specular surface with high pre ? cision because the calibration error has little effect on the result of the testing. Computer simulation and experi? ment validate the feasibility of the proposed method.

Ratioing radiometer (RR) is a key instrument which can track the on-orbit degradation in bidirectional reflectance distribution function (BRDF) of on-board solar diffuser (SD), and its response to sun angle of incidence (K factor) is an important parameter which need to be measured pre-launch. A brief overview of the principle of RR is provided in this paper, K factor of each band of RR is acquired after several round of tests, which take halogen lamp in the lab instead of sunlight outdoor as light source . Uncertainty of K factors at 470, 650, 825 nm are acquired on the base of the data and error analysis. Result shows that the uncertainty of the K factor at 470 nm is 0.48% and within 0.16% at 650 nm and 825 nm, which meet the requirement of K factor uncertainty, providing valid basis for estimation of on-orbit calibration uncertainty and correction of the calibration coefficient.

In order to produce single-side band (SSB) light needed by radio over fiber (RoF) system with the SSB effect of one-period oscillation based on an optically injected semiconductor laser, the injection conditions and influencing factors are investigated by numerical simulation method. By the rate equations of the optically injected semiconductor laser under different injection intensities and frequency detunings, the ranges of producing SSB effect are found. Two special cases of weak injection and strong injection are selected, in which the influences of various parameters on the SSB effects are researched, respectively. The results show that in the cases of weak and strong injections, SSB effects become obvious with the decrease of the normalized bias current density and linewidth enhancement factor. In the case of weak injection, the SSB effect becomes good with the increase of the frequency detuning. However, it is necessary to decrease the frequency detuning for producing the SBB effect well in the case of strong injection. In addition, SSB effect gets enhanced with the increase of the cavity decay rate in the case of strong injection. Therefore, in order to get a good SSB light, the appropriate laser type and external injection parameters should be selected.

The evolvement of defocus aberration in unstable resonator is studied in geometric optical approximation. Linear correction in a positive branch cavity is obtained analytically. The simulation results from oxygen iodine chemical laser show that the smaller the magnification of the resonator is, the greater the influence of aberration evolvement becomes. Deformable mirror located at concave mirror can obtain the best compensation effect. The value of β can be reduced by 35% on average with considered aberration sensitivity compensation compared to the direct compensation.

A general expression of the photoluminescence (PL)-spectral shape depending on the size distribution of quantum dots (QDs) in the condition of low doping concentration is presented, using the effective mass approximation and supposing a Gaussian distribution of QD sizes. Effect of the size fluctuation on the PL-broadened line is discussed. As an example, the PL-broadened lines of both IV-VI CdSe QDs and II-VI PbSe QDs are calculated. There is evidence to show that the calculated PL intensity, PL-peak wavelength and full width at half maximum of the PL-broadened line are in consistent with the experimental measurements. The size distribution of QDs has primary effect on the PL-broadened line. The PL-broadened line is an inhomogeneous broadening.

The modulation of dielectric constant and loss at terahertz (THz) frequency of CaCu3Ti4O12 (CCTO) ceramics is achieved by doping Nd2O3. Nd2O3 doped CCTO samples are prepared by solid-state reaction method. Structure analysis shows that the Nd ions do not affect the basic crystalline structure of CCTO. With the help of morphologic characterization, one can find that grain size increases when increasing the concentration of Nd2O3 first. But it decreases when the concentration of Nd2O3 exceed 0.6 % (mass fraction). An evident refinement effect occurs when the concentrations of Nd2O3 increases monotonically. THz spectroscopic measurement shows that the variation of real part of dielectric constant is contrary to that of grain-size of CCTO, while the loss variation is in agreement with the trend of grain-size variation. The results indicate that the dielectric constant at THz frequency of CCTO ceramics can be modulated effectively by doping Nd2O3.

The absorption and photoluminescence (PL) spectra of PbSe quantum dots (QDs) with different sizes and doped in organic solvent-hexane are measured by using the transmission electron microscopy (TEM), nearinfrared (NIR) absorption spectroscopy, fluorescence spectroscopy and time- resolved spectroscopy at room temperature. An empirical formula of the first absorption-peak wavelength and PL-peak wavelength varying with the size of QDs are obtained. The PL-lifetimes of PbSe QDs are determined by analyzing transient PL-decay curves. It is shown that the lifetime depends on both the surface defect and the size of QDs. The widest distribution of the lifetime ranges 1.44~11.96 μs, which can be deduced from two extreme conditions, i.e., the PL transition is only a direct interband transition and/or only a defected state transition in the range of particle size used. On the other hand, the PL lifetime is dependent weakly on the size of QDs, it will decrease with the increase of the particel size. As an example, the averaged lifetime is among 7.17~6.72 μs for the QDs diameter in the range of 2.7~5.7 nm.

Based on the modified square-operator method and the Fourier collocation method, the transmission characteristics of dipole, tripole and quadrupole solitons in two dimension parity-time (PT) symmetric triangle- Gaussian potential are studied. The results turn out that the field distribution of tripole solitons changes with altering parameter, and no stable tripole soliton exists. For dipole and quadrupole solitons, the powers increase with the propagation constant and decrease with potential depth. Further, it is found that the stability of solitons is controlled by the potential depth of crystal lattice and the propagation constant. For given potential depth, there exists a stable region. With raising potential depth, the size of stable region decreases firstly and then goes up for dipole solitons; whereas it wave-like increases firstly and then decreases for quadrupole solitons.

In order to measure the millisecond pulse laser irradiation of transparent material real-time stress and stress strain evolution process, in view of the high power solid laser interaction with materials, the method of Mach- Zehnder interference to get the interference fringes by the material damage is adopted. The on-line stress and the evolution of the material are obtained through the analysis and the processing of the change of the interference fringe. Single-crystal silicon is selected as experiment material and comsol simulation model is established based on the optical interference theory. Based on the theory and the simulation, the experiment is carried out. The error of experiment and simulation in r(x) direction is between 11.7% ~33.91%, and the error in z (y, z) direction is between 20.25% ~31.34% , which shows measuring the stress of the transparent material with Mach- Zehnder transient interference method is feasible. This provides a new method for the research of real-time stress damage and its evolution process of laser interaction with none-transparent materials.

Satellite navigation urgently requires large aperture star sensor. Based on the research objective of large aperture and light weight, alarge aperture catadioptric optical system is designed using an R- C system and a spherical compensating lens.The field of view of the star sensor is 18°, the focal length is 719 mm,the diameter of the entrance pupil is 164 mm, and the working waveband is from 0.45 μm to 0.9 μm. The telecentric image plane design decreases the effect of calculating the position of centroid caused by the imaging plane defocussing and increases the irradiance uniformity. The initial parameters are calculated based on aberration theory. Then, ray tracing and optimization are performed by CODE V software.The abscured ratio is 0.317.The MTF is more than 0.81@ 26 lp/mm, which approaches the diffraction limit, 80% energy encircled is within 3×3 pixels,the lateral chromatic aberration is less than 2 μm, and the centroidal deviation is less than 2 μm.The internal baffle, external baffle, second-mirror baffle, and blocking rings are used to decrease the stray light level. The stray light of the opticalmechanical is simulated and analyzed using TracePro software,and the results show that the point source transmittance is between 10-7 to 10-4 in the range of the incident angle 6°~90° incident angle, which satisfies the requirements of application.

Influence of manufacturing errors of micro lens array on optical imaging performance is discussed to quest what distributive surface errors may benefit the improvement of optical performance. Transformation matrix between surface error and corresponding wavefront aberration is established, which achieves high deviation accuracy between simulated and computed wavefront aberrations. Zernike polynomials with orthogonality are utilized as the interface between optics and manufacturing, representing the surface error and wavefront aberration of the finished optical surface with the slow slide servo, acting as the interferogram data imported into the designated surface of 7 sub eye optical system afterwards, thus reflecting the change of distortion, spot diagram, point spread function (PSF) and modulation transfer function (MTF) at different locations quantitatively. Results show that errors with the same distribution but gradually increasing peak-valley (PV) values make the distortion and MTF change with gradient, and two-dimensional distribution of PSF has a remarkable correspondence with field; left and middle distributive wavefront aberrations with the same PV value improve the distortion, spot diagram and MTF at specific relative locations, but worsen optical performance at other locations. With overall consideration of various optical parameters, right distributive surface error benefits the improvement of optical performance, which provides surface shape compensation model for ultra-precision manufacturing process of freeform optics.

Conventional backlight system of liguid crystal display (LCD) always uses side-in light emitting diodes (LEDs). It requires that the thickness of the light guide plate should be larger than LED′s light-emitting section width. To solve this problem, a free- form optical coupling module for side- LED backlight is proposed, which includes collimator lens and a free- form reflector. The light is firstly collected and collimated by immersing collimator lens, and then reflected and gathered into the LGP′s incident surface. By using Snell′s law, differential geometry method and aplanatic principle, the detailed design of the module is presented, and the feasibility is shown by optical simulation. Simulation results show that by choosing 0.4 mm×0.4 mm LED chip as the light source, the thickness of the light guide plate is reduced 0.6 mm, and the light utilization can still reach 96.23%. Compared with the conventional structure, the light utilization increases by 11.22%. The optical coupling module can realize a thinner backlight module effectively, and simultaneously help to restrain the hot phenomenon.

There are several methods to design dual-band-pass optical filters, such as automatic optimization, design using buffer and combinatorial layers, F-P filter with thick spacer layers; repeating blocks of F-P filter with double peaks and F-P filter with a fractal structure, etc. But they have certain limitations either in design that has specific requirements on band-width and distance between two channels, or in the technique implementation of the film stack. Using the method of combining two F-P filters with a transmission band, which is obtained from optimization of target fitting, the problem of designing a wide band-width and large channel span dual-band-pass filter is effectively solved. Using the materials of Germanium and Silicon monoxide, a good spectrum performance dual-band-pass optical filter is designed with a layer number of 38. The relative band-width of both path-bands are 9%, the ratio between two channels’wavelength position can be adjusted from 1.4 to 5.0, the steepness of all the band edges are no more than 2.0%. This kind of coatings structure has strong technological practicability as well as good adjustability of both pass-band-width and channel position.

Abstract Terahertz time domain spectroscopy (THz-TDS) is used to investigate the optical properties of nematic liquid crystals E7 and 5CB under the external magnetic field, electric field and optical field in the THz range. It is systematically summarized that the optical property changes of nematic liquid crystals under different external fields. It is experimentally observed that a negative magneto refractive index change under the magnetic field and a positive refractive index change under the electric field. The maximum values of magneto and electric refractive index changes reach - 0.087 and 0.051, respectively. The physical mechanism of photorefractive effect is the same as electric refractive effect, and the maximum value of photorefractive coefficient is 0.015 under the power of 532 nm laser with 7.961 W/cm2 output. These research results are significant for the key THz devices such as tunable phase shifters, filters and the spatial light modulator in THz technology and applications.

To suppress the spatial mismatching and the phase-shift error in dynamic interferometer, the phase correlation algorithm and carrier squeezing interferometry are used respectively. The former takes the edge of test beam spot as the match characteristics to achieve the matching precision with pixel level of 4 phase- shift interferograms in space by registrating the test spot. The latter achieves separating the phase lobe and the error lobe in Fourier spectrum through the rearranging of 4 carrier phase-shift interferograms, therefore the phase error can be suppressed by extracting the phase lobe. The experimental result shows that the mismatching error and the phase- shift error are suppressed well by the two techniques, and the corrected result accords with the interferometer, where the differences between their root-mean-square value and peak-to-valley value are 0.0057 λ and 0.0235 λ respectively. The phase correlation algorithm is not affected by factors such as intensity distortion, and the carrier squeezing interferometry can also suppress the phase error whose spatial frequency is twice the fringes caused by phase-shifting devices and phase error with the same spatial frequency as the fringes caused by the intensity distortion error.

A theory model of the four-level type semiconductor quantum dot system under the mechanism of electromagnetically induced transparency (EIT) is proposed. The model is composed of a semiconductor quantum dot (SQD) system interacting with a weak, linear-polarized probe field with two orthogonally polarized components under the applied longitudinal magnetic field and two strong coupling control fields. By using the multiple-scale method, the stability and collision dynamical characteristics of two coupled temporal vector optical solitons in the semiconductor quantum dot media are analytically investigated. It is shown that the collision properties of two coupled temporal vector optical solitons are correlated with their initial phase shift. Especially, when two solitons components are in phase or out of phase, the collisions between them are almost elastic without energy transfer. While the initial phase shift is π 2 , they will be separated from each other after their collision and there is energy transfer between two solitons.

A new program based on the spatial light modulator(SLM) to modulate the phase and generate pseudothermal light is put forward. The influence of ghost imaging with different spatial light modulator pixel array arrangements is discussed. To improve the performance of pseudo-thermal light field, the design of spatial light modulator pixel array arrangement based on genetic algorithm is studied emphatically. The result shows that the spatial light modulator program overcomes the limitation of the ground glass program and the second- order correlation of the pseudo-thermal light produced by the spatial light modulator program is quite good. The light field generated by the spatial light modulator program can meet the needs of ghost imaging and the quality of the image is quite high. So the spatial light modulator program has an important reference for the new pseudo-thermal light source of ghost imaging.

The interaction of the qubits is added in Rabi model and the adiabatic approximation method is used to solve this model. The effect of the entanglement on the interaction parameter is also investigated. A notable result indicates that it can prolong the entanglement time or improve the entanglement degree by using an appropriate interaction parameter. As the generation and preservation of entanglement plays an important role in quantum information processing.

In the process of spaceborne camera imaging, the brightness of the scene changes with atomosphere and ground target. In order to obtain ideal images, an automatic exposure method based on land- atmosphere radiative transfer model for spaceborne camera is proposed. The irradiance model is established at the pupil of spaceborne camera according to the land-atmosphere radiation transmission characteristics. After analyzing the influence of atmospheric aerosol in remote sensing image, improving the irradiance model, and on this basis an automatic exposure is proposed. Through calculating the total irradiance and the ratio of ground target irradiance in the total irradiance, and adjusting the automatic exposure parameter of spaceborne camera to improve ground targets information as much as possible. Then the adaptive Laplace filter parameters are determined according to the atmospheric aerosol optical thickness, in order to enhance the details of the remote sensing images. The experimental results shows that the quality of the remote sensing images are improved greatly, on account of promoting information and contrast of remote sensing images with the proposed method.

Hyperspectral target detection is a great deal of attention in the field of remote sensing signal processing. The KRX algorithm based on kernel machine learning can make full use of nonlinear spectral characteristics among hyperspectral bands. Therefore，it can get better detection results in the original spectral feature space. Aimed at the defect that the complexities of KRX algorithm is high in calculating the detection process and unable meet the requirement of rapid processing. A real-time anomaly detection method is proposed based on recursive kernel function. The recursive thought of Kalman filter is introduced, which puts forward a nuclear recursive hyperspectral anomaly target detection algorithm. From the perspective of spectral analysis, with Woodbury′s lemma, the kernel matrices can be updated by the kernel matrices of last pixel. It avoids repeat computation of high-dimensional data matrices. Experimental results show that the accuracy of anomaly detection is improved and testing time of the algorithm is reduced at the same time when compared with the traditional RX, causal RX and KRX algorithm.

In remote sensing observation, the target radiation information contains background radiation scattered by the atmosphere entering the field of view of the sensor section, which is adjacency effect making the feature edge blurred, contrast lower. In order to obtain accurate target information from remote sensing image, adjacency effect correction is necessary. Using MODIS aerosol products and importing a new adjacency effect correction coefficient to correct adjacency effect of GF- 1 satellite multi- spectral remote sensing images, which are based on the atmospheric radiation transfer model. The results show that after correction, the contrast and the definition of remote sensing image are increased obviously, meanwhile feature information is more abundant.

In order to achieve the identification of different mineral compositions, a shortwave infrared imaging spectrometer for spectral analysis of the ore are developed. Based on this instrument, the image information and spectral information of the various minerals are obtained. The design principle of imaging spectrometer is described and image quality of the entire system is analyzed based on the result of optical design. The system performance is tested using monochromatic collimated light method and the center wavelength and spectral resolution for each spectral channel are obtained. Test results show that the spectral resolution is better than 10 nm which meets the application requirements. The rock samples are tested using the developed imaging spectrometer and the spectral curves of rock are obtained for spectral analysis. The experimental results show that the imaging spectrometer can identify different components of ore with high accuracy. The new designed shortwave infrared imaging spectrometer has the advantages of high resolution, simple structure, small size, light weight which is facilitate the application in airborne imaging, and it is useful for the application in geological exploration.

The precision of gas detection is affected by each function module performance of the system, when tunable diode laser absorption spectroscopy (TDLAS) is applied in gas detection. So the output current noise spectral density and the responsivity characteristics of photo detector are studied. The paper deduces the expression of the output current of photo detector, and the conclusion that the current is related to laser relative intensity noise (RIN), which exits in TDLAS experimental system. Effect of RIN on the output current of photo detector is studied by simulation, and the curve of current noise spectral density on different conditions is given. To avoid the photo detector responsivity being affected by ambient temperature, a real- time correction method is designed with the given principle and formula. Taking ammonia gas as an example, the concentration curve is corrected by using the method.

In order to improve the accuracy of near-infrared (NIR) spectroscopy measurement, the method with medium concentration sample as reference for relative measurement is proposed. Firstly, theoretical analysis of absorbance error sources with background reducted is presented, which shows that errors caused by sample cell and optical fiber loss can be reduced by using medium concentration sample as reference. Furthermore, NIR transmission experiments on glucose aqueous solution and 3% intralipid solution as phantom are performed with glucose used as analyte. In the double-beam experiment on glucose aqueous solution, root mean square error of calibration (fRMSEC) and root mean square error of cross validation (fRMSECV) of the partial least squares (PLS) regression model using medium concentration sample as reference decrease respectively by 36.6% and 41.0% compared to the model with pure water as reference. Meanwhile, in the intralipid phantom experiment, fRMSEC and fRMSECV of the PLS regression model using medium concentration sample as reference decrease respectively by 66.3% and 39.3% compared to the model with glucose- free 3% intralipid solution as reference. The results show that the accuracy of NIR transmission spectroscopy analysis can be effectively improved by using medium concentration sample as reference.concentration sample

Interferometric hyperspectral imaging can obtain the spatial information and spectral characteristics of the target. It plays an important role in many fields such as biomedicine，material analysis，food safety and cultural relic archaeology. The interferometric hyperspectral imaging based on symmetric wedgy cavity provides a new method for spectral detection. By analyzing the interference principle and working mode，the spectrum recovery method is studied. In order to eliminate the effect of image-plane macula on spectrum recovery，an interferogram correction algorithm is proposed. A fast subpixel image registration algorithm based on local phase correlation can realize accurate extraction of the interference data in holistic push-broom mode. A spectrum recovery method based on matrix inversion is presented by discussing the systemic spectral transfer matrix. A prototype is developed for a spectral imaging experiment and the preliminary recovered results are obtained with the proposed spectrum recovery method.

Food quality is greatly dependent on the security of the food packaging process，which has been widely developed to inhibit food spoilage and to prolong the shelf life for food products. Gas in scattering media absorption spectroscopy is used as an optical noninvasive method to estimate the gas content in food packages. A diode laser with central wavelength of 760 nm is used to record an oxygen spectroscopic signal, and then to estimate the oxygen content by investigating the gas exchange in the package. The experimental results show that the technique can be used to determine the oxygen concentration and to assure the integrity and security of food packages.

Diode laser cavity ring-down spectroscopy (CRDS) for the measurement of NO2 concentration (volume fraction, hereinafter the same) in the atmosphere is presented. The output spectrum of the diode laser is optimized by changing the external modulation signal. The effective cross- section of NO2 is a convolution of the highresolution absorption cross-section and the laser spectrum. The interference of O3, water vapor and other gases has also been investigated. The limit of detection is 6.6×10-11 for NO2 at 1 s time resolution. The 1σ accuracy of the measurement is ±4.5%, with the largest uncertainty being the effective NO2 absorption cross-section and RL (ratio of ring down cavity length and single absorption optical path of the gas in cavity). Comparison of this system to the incoherent broad-band cavity-enhanced absorption spectroscopy (IBB-CEAS) instrument for NO2 concentration measurement shows linear agreement (R2=0.99) with slope of 0.988±0.005 in laboratory. The system is employed to measure the ambient NO2. The NO2 concentration varies from 1×10-8 to 5×10-8 with an average level of 3.5×10-8. To verify the results of the CRDS instrument, a long path differential optical absorption spectroscopy (LP-DOAS) system is used to measure ambient NO2 simultaneously. The data sets for NO2 exhibit high correlation and good agreement within the combined accuracy of the two methods. Linear fits show a slope of 1.051±0.006 in ambient air. The experimental results show that the diode laser cavity ring-down spectroscopy can realize high sensitivity and high temporal resolution in situ detection of NO2 in the atmosphere.

Non-uniform illumination scene is difficult to meet the single priori assumptions of existing lighting estimation method, therefore a regional-oriented non-uniform estimation method is proposed. The affecting of Lambertian object surface reflection is considered to estimate the illumination, the object surface reflectance of the homogenous regions is analyzed, and the exemplar-based support vector machine model is used to build regional illumination model of typical homogenous regions. The proposed method effectively improves the estimation accuracy about non-uniform illumination by acquiring illumination model of homogenous regions. Experimental results show that on the database of standard realistic scenes, the proposed illumination estimation method is superior to other current advanced methods.