Based on the High-resolution Transmission (HITRAN) molecular spectroscopic database, the absorptions of the THz wave by the main atmospheric molecules were contrasted. According to the Mie theory and with the fog particle size distribution considered, the average scattering characteristics of fog droplet particles were analyzed with different incident wavelengths. The transmissivity and the reflectivity and the forward and backward scattering intensities of the THz signal in fog,as well as the infrared light, were investigated with Monte Carlo method. The result shows that in THz region, the lower the frequency, the higher the transmissivity, the lower the reflectivity, the weaker the backward scattering intensity; additionally, with a same distance the THz wave has a better transmission capacity than the infrared light; meanwhile, the forward scattering intensity of the infrared light is stronger than the THz wave with a same scattering angle. The research in the paper is of great significance to the application of the terahertz technology on the atmospheric space.

Cross-spectral density function of polarized and partially coherent laser propagated in turbulent atmosphere was determined based on the extended Huygens-Fresnel principle and Collins Formula. Analytical expressions for spectral intensity, expansion radius and barycentric position wander of polarized Gaussian-shell model beam were obtained under horizontal transmission at different distances of external fields. The beam extension and drift of the polarized laser polarized laser propagated in turbulent atmosphere were simulated, and the changing information of laser beam′s extension and drift in the same propagating distance with different polarizing angle,initial waist widths, and wave length were got. Similar simulation was also done using the different wavelengths and the same polarization angle but with different propagation distances. The results indicated that the spread and wander of polarized and partially coherent laser propagated in turbulent atmosphere are dependent on the polarization angle and initial waist width. The spread and wander of polarized laser beam at 45° show symmetry as polarization angle varies. With initial waist width less than or equal to 0.5 mm, the spread and wander were increasingly affected by atmospheric turbulence.

The algorithm for retrieving atmospheric Precipitable Water Vapor(PWV) was introduced by several Moderate Resolution Imaging Spectroradiometer(MODIS) near-IR channels. Three-channel ratio weighting method is applicable for water vapor retrieval over Wuhan by comparing several commonly used algorithms. The credibility of the algorithm is verified in contrast to the EOS water vapor products. The PWV in recent ten years (2001-2011) over Wuhan were analyzed by the three-channel ratio weighting method with the aid of remote sensing image processing software ENVI combined with actual geographical location, climate conditions and urban status of the development. The results show that the PWV over Wuhan has a distinct decreasing trend in the autumn and winter. With the help of scientific statistical software SPSS, unary regression model was used to analyze the relationship between the MODIS derived PWV and ground-based meteorological factors, such as temperature, pressure and relative humidity. The results show that PWV derived from MODIS has positively correlated with temperature, negatively correlated with pressure, has little correlation with relative humidity, except that when the temperature is the same, in which condition the two are positively related.

In order to achieve the multi-vibration source surface acousto-optical effect,two vibration sources were used to generate two low-frequency surface wave on the liquid surface at the same time,and also the clear,stable,high contrast acousto-optic diffraction fringes were observed.When the two surface waves′ frequency with multiple relations,the spot positions of diffraction pattern are same as the smaller frequency alone and are part of same the larger frequency alone.The diffraction fringes of single vibration source,and the interference fringes of double vibration source were observed when they don′t have multiple relations.It was derived that the analytical expressions between multi source diffraction field and the wavelength of surface waves or and amplitude.The theoretical analysis agree well with experimental results.

In order to eliminate the Moiré fringe and crosstalk existed in parallax barrier based autostereoscopic display, a new design of slanted zigzag staggered parallax barrier was presented for autostereoscopic display. The slits were divided into sections at half the height of a pixel and the adjacent two sections were symmetrical triangles based on slanted barrier. This method can decrease the probability of the perceived adjoining sub-pixel seen through the same slit when compared with the slanted barrier, thererfore, crosstalk can be reduced and the field of viewing zone can be extended. The simulated and measured results show that the proposed method can increase the viewing zone by 25% more than that of slanted barriers with a decrease of only 4.5% of the Moiré fringe. And it has higher practical value for autostereoscopic display.

In order to depth study transmission characteristics of surface plasmon polariton based on strip structure, surface plasmon polariton excitation was achieved by using grating coupling. The transmission characteristics which is relation to film thickness and incident angle were obtained though adopting to change he metal film thickness and angle of incident light. The results show that reduction of the metal film thickness will result in rapid transmission bandwidth reduction to a lower transmission rate. Moreover, the incident light angle changes as the efficiency of light transmission varies. The results are significant of nanoplasma polarization couple of semiconductor equipment research.

In order to improve the precision of fiber-optic gyroscope, a novel fiber optic-gyroscope with double optical length was presented. By employing two polarization beam splitters, polarized light propagated twice along the slow and fast axes of the polarization maintaining fiber sensing coil in sequence to double its effective optical length and precision further. The thermal induced non-reciprocity in the proposed fiber-optic gyroscope was analyzed according to its special structure. With finite element analysis technique, modeling and simulation of the Shupe bias errors were also conducted. By modifying the 90°splicing point to the middle of the sensing coil or choosing appropriate fiber with special refractive index temperature coefficients , the Shupe bias error can be reduced significantly, which is low enough to meet the requirement of fiber optic-gyroscopes with high performance.

Based on the encoding requirements of the continuous variable coherent optical communication in the single beam light,a novel encoding scheme by the joint modulation including magneto-optic modulation and electro-optic modulation was proposed.According to the mapping relationship between Stokes parameters and Poincare sphere,the coding principle of the joint modulation is analyzed in Stokes matrix theory.Then a single beam optical system is set up for encoding.And based on the needs of encoding,a driving circuit of magneto-optic modulatior and a circuit of random number generator are designed.By homodyne detection technique,the Stokes parameters are measured,and the error rate is estimated by LabVIEW procedure.The raw data show that the error rate is lower than 3.60%,which verify the feasibility of the encoding scheme.

In order to achieve the measurement of the pressure in the harsh environment of strong electromagnetic interference, high temperature, high pressure, to further improve the miniaturization of sensors and reduce the cost of sensors,an optic fiber micro electro mechanical systems pressure sensor based on white light interferometry was produced. Fabry-Perot(F-P) cavity composed of silicon and glass was producted by the means of lithography, anodic bonding and chemical etching which was based on micro electro mechanical systems technology. F-P cavity with optical fibers were welded together through the carbon dioxide laser. The sensor was demodulated by the cross-correlation relationship between Fizeau interferometer and F-P cavity which is based on white-light interferometry techniques. Pressure sensor experimental was done,and the experimental results show that the sensor has a high sensitivity and linearity of 9.012 7 nm/kPa and 99.9%, respectively, the repeatability of sensor is 0.1%.The study has guiding significance for the production of low-cost and high-consistency fiber FP sensors.

Flattop broadband wavelength conversions based on difference frequency generation were fulfilled by utilizing step-segmented quasi-phase matched gratings.For the same waveguide length,high conversion efficiency,flat response and broad signal bandwidth can be obtained simultaneously by adding the segment number of quasi-phase matched grating and optimizing the poling period of the first segment and the period shifts between adjacent sections.Analysis of the structure parameters on conversion efficiency,signal bandwidth and response flatness is performed as well.The conversion bandwidth in a 3-cm-long waveguide reaches 166 nm,which is over the whole conventional band and long-wavelength band,meanwhile the maximum efficiency is -0.55 dB and the peak-to-peak ripples less than 0.2 dB.In addition,the comparison among step-segmented gratings,sinusoidally chirped optical superlattices and segmented gratings is carried out,the step-segmented gratings shows higher conversion efficiency and flatter response than the other two gratings,and has much broader bandwidth than sinusoidally chirped optical superlattices.

A fusion method of infrared thermal wave images based on nonsubsampled shearlet transform and weighted non-negative matrix factorization was proposed. After infrared thermal wave image sequences are decomposed by nonsubsampled shearlet transform, dynamic weighted non-negative matrix factorization algorithm is adopted for fusion processing of low-frequency coefficients. The weighted coefficients of algorithm are adjusted dynamically according to the mutation degree of image pixel. As a result, the defect areas of infrared thermal image are highlighted. The fusion rule based on area sum-modified-laplacian is used for high-frequency coefficients to preserve the defect edges and details. Experimental results show that, the method proposed in this paper has superior performance in subjective visual effect and objective quantitative evaluation indices such as edge preserving degree, correlation and running time. The proposed method is fast and effective. It can keep the edges of infrared thermal images more complete and clear. In addition, the proposed method can be adopted for image fusion of multi infrared thermal image sequences effectively. Therefore, the proposed method has high practical value in the thermal wave nondestructive testing.

A measurement method of the high dynamic range laser focal spot was proposed. First of all, the mathematical model of schlieren method to measure the far-field focal spot was constructed,the main lobe intensity amplification coefficient and the laser spot amplification coefficient were confirmed, and the parameters were calibrated by automatic alignment laser beam; Secondly, the schlieren ball was put in focus position of side lobe laser beam to shade the spot centre and side lobe image was captured accurately by integrated diagnostic beam fast automatic alignment system; Finally, the schlieren reconstructed algorithm was optimized by calculating side lobe image centre and image fusion, and the error of traditional schlieren reconstruction method for side lobe center was decreased and the obvious edge of reconstructed image was eliminated. The application in parameter measurement integrated diagnostic system of the high power laser facility to measure far-field laser focal spot shows that the method can measure the far field distribution of high dynamic range laser focal spot exactly if the parameter of the mathematical model is calibrated accurately and the schlieren reconstructed algorithm is optimized.

A novel infrared polarization target detection method based on matrix recovery and double window filter, was proposed to remove the complex desert background clutter in the detection of dim and small target. Data analysis demonstrated that similarity of infrared polarization Q image background was the highest. Using morphological filter enhance the similarity of background. Q image background could be seen as a low-rank matrix, dim and small target could be seen as redundancy data which break the similarity of background. So background suppression mathematics model based on stable matrix recovery was build. Detection was completed after double window filter segments targets in background suppression result. Experimental results on real-world infrared polarization images and comparisons with state-of-the-art methods can demonstrate the effectiveness and robustness of the proposed method, and it was suitable for engineering application.

A novel image denoising algorithm based on undecimated dual-tree complex wavelet transform domain was proposed. Firstly, the dependency among the real and imaginary parts of undecimated dual-tree complex wavelet coefficients in the same direction was analyzed. According to the dependency characterization and empirical joint distribution of the original clean images, an elliptically contoured and anisoropic bivariate non-Gaussian statistical model was established to fit the empirical joint distribution of real and imaginary parts. Then the joint distribution as a prior model was modeled with an adaptive and anisoropic non-Gaussian bivariate statistical model as well as reflects the dependencies among coefficients. It finally uses a maximum posteriori probability from noise image to estimate the original image wavelet coefficients,so as to achieve the purpose of denoising. A denoising rule with the simple closed-form solution was derived from the model. The experimental results demonstrate that the proposed method can obtain better performances than other existing outstanding denoising algorithms in terms of peak signal-to-noise ratio and achieve a better visual quality. It also offers a better recovery of texture information compared to others.

In order to evaluate the performance of laser jamming objectively, precisely and quantitatively, the definition of image edge strength and its computation method are provided, and an objective image metrics based on the edge strength similarity was proposed. The metrics evaluate the laser jamming performance by computing the similarity between the target image and laser jamming image. The higher the similarity between target and background is, the better the laser interference performance is. Experimental results of laser interference in and out the field of view show that the proposed metrics could realize quantitative appraisal of laser jamming performance on CCD imaging detection system and have a better consistency with the eye′s experimental data in the prediction of detection probability than common clutter metrics by taking use of the Search_2 dataset.

A recording method based on scanning the optical path difference was proposed in low coherence off-axis digital holography,due to the coherence length of the light source limit the detected area of the object wave.First,the different areas of detected plane were scaned by changing the optical path difference between the reference wave and the object wave.Then,the phase distribution of each scanning area was obtained by numerical reconstruction for each scanning area of digital hologram.At last,phase stitching technology was applied to stitch each scanning area to achieve the full field of the view of the object wave.

A non-contact Fluorescence Diffuse Optical Tomography (FDOT) system based Electron-Multiplying CCD(EMCCD) was setup for in vivo imaging of mice. A novel Data-Extraction-Extension-Method (DEEM) was investigated to avoid the complex focus correction calculation for the optical lens and alleviate the ill-posedness of the inverse problem. Accordingly, a non-contact FDOT image reconstruction method based on the DEEM was developed. A lot of FDOT experiments were carried on the solid phantoms, which proved that the best reconstruction results can be achieved when the Data-Extraction-area is half of the whole projection of the cylinder phantom on the CCD and is decomposed into three sub-areas. To further validate the method, the in vivo mouse with fluorescence target embedded was fabricated and the FDOT experiment was carried on. Reconstructed images from FDOT system and those from the Micro-CT demonstrate that the combination of the non-contact system and the proposed reconstruction method based on the DEEM can obtain the location and yield of the fluorescence target in the mouse correctly. The system can be further developed to detect the subcutaneous tumor of the small animals.

An improved algebraic iterative algorithm was proposed to solve the problem that reconstruction of gas diffusion can barely be completed by the conventional algebraic iterative algorithm. Under the condition of fan beam geometry and double projections, the prior matrix was introduced in the iteration steps and the results processed by median filter every few iterations. Taking Gaussian plume model as test object, the effect of iterations, relaxation factor and different filter using strategies on the reconstruction results were analyzed. The experimental results shows that the mean square error and peak error reach the basic convergence and the peaks can be controlled in a certain range when the number of iterations is 500 and the relaxation factor is 2. Compared with the conventional algebraic iterative algorithm, the improved algorithm is better on the reconstitution indicators of mean square error and peak error. Furthermore, the peak position can be located more accurately and tail peak can be reconstructed successfully through the improved algorithm and the improved algorithm is robust to noise.

An improved reconstruction algorithm of the boundary surfaces within 3D images was proposed based on the fractional differential, which can reconstruct more detailed structures of the 3D irregular biomedical objectives. Thus, the deficiency of reconstruction more detailed information in the was proposed based on the fractional differential, which can reconstruct more detailed structures of the 3D irregular biomedical objectives. Thus, the deficiency of reconstruction more detailed information in the traditional algorithm was overcome. According to the separateness of the Fourier Transformation of the fractional differential, the 2D calculus was extended to 3D, and the 3D discrete templates were deduced. Due to the nonlinear enhancement, the 3D fractional differential can enhancement the 3D slice data significantly. By comparison with the traditional reconstruction method of the 3D boundary surfaces, the improved algorithm could detect and extract more detailed 3D structure information by using the 3D fractional differential. The proposed algorithm was applied in the reconstruction of the 3D irregular structure of the neuron within confocal microscopy images, which demonstrated the high efficiency and property, it can be easily extended to other research fields of 3D visualization.

In optical diffraction tomography with specimen rotation,the set of captured frequencies exhibits a missing space called missing apple core,an algorithm,in which Fourier mapping algorithm was combined with iterative constraint algorithm,was proposed to acquire the missing frequencies and reconstruct a high-resolution refractive index map.First,based on the theory of digital holographic microtomography with sample rotation,the experiment system was set up and the digital holograms were acquired at regularly-spaced angular positions within 360° viewing angle.Then,the complex field images were calculated from the holograms.Last,the high-resolution three-dimensional refractive index map was reconstructed by the proposed algorithm.The experimental results demonstrate that the algorithm is feasible and effective for acquiring the missing apple core frequencies and achieving the high-resolution three-dimensional refractive index distribution.

The effect and mechanism of smokescreen jamming on TV homing seekers were investigated by seeker captive flight jamming test,in which a TV homing seeker was hung up on an unmanned airship.The data of smokescreen jamming effect on the TV seeker in flight is obtained with the TV seeker disturbing by smokerscreen.The test results shows that smokescreen jamming has much effect on the tracking status of TV seekers,tracking error,measurement of line-of-sight angle and its angular rate.A rational explanation for the laws of smokescreen jamming effect is presented based on the principle of stabilization of seeker optical axis.

A Yb∶YAG thin disk laser with a novel four-pass pumped structure and direct water cooling device was designed. The multi-mode pump radiation was from a fiber-coupled 940 nm diode laser. The Yb∶YAG disk with 10 mm diameter and 500 μm thickness was employed. The Yb3+ atom fraction was 10%. The direct cooling arrangement was put forward,tap water was contacted with the Yb∶YAG through a V groove. The four-pass pump coupling system was well designed with a pair of rectangular prism and a focusing lens which had a diameter of 50 mm and focus of 50 mm. Then simulated the stability of the resonator and calculated the radius of the laser spot in different position of the resonator with the different cavity length. Different types of laser cavity were set up. With the output coupling rate of 5%,the maximum output power of 3.28 W at 1 031 nm was obtained in F-P resonator. The beam quality M2x=1.79, M2y=1.86. The slope efficiency was 20.5%.

In order to satisfy the needs of the rate of fuze pulse front edge, laser pulse width and power in the detection system of laser proximity fuze, by the theory analysis of RLC discharge circuit, double transistors driving high-speed metal-oxide semiconductor field-effect transistor was used as the high-speed switching, and Microprocessor C8051FXXX was adopted to produce pulse trigger signal, a drive power of laser proximity fuze with high-power high-speed and narrow pulse was designed. Through PSPICE software analysis and experimental verification, the drive power can realize that pulse front edge is about 4 ns, pulse width is about 10 ns, and peak current of the laser can reach 50 A. The research effectively improved the ability of system detection range and anti-cloud and dust interference.

To meet the applications of high energy laser annular beam in near-field and far-field, the expressions of light field distribution and the light intensity distribution in near-field region and far-field from electromagnetic wave diffraction integral equation were obtained and analysed. It can be concluded that the light intensity distribution was decided by the finite aperture, central obscure ratio and transmission distance of gaussian beam. Furthermore, atmospheric turbulence was introduced, by the method of phase screen, the atmospheric transmissions of annular light beam in different turbulence intensities were simulated. Due to the influence of atmospheric turbulence, the consequences of far-field spot distortion, spot crushing, beam expansion and drifting were studied and analysed. Finally, the numerical simulation and experiment of annular light beam atmospheric transmission in near-field were carried out. The results show that the spot central intensity becomes stronger and stronger, the spot intensity gradually tends to be more uniform, and the average intensity is near gaussian distribution with the increase of transmission distance. Because of the influence of atmospheric turbulence, the near-field annular beam dispersion and spot distortion increases also.

Backscattering noise is an important factor to restrict the accuracy of resonator fiber optic gyroscope.The investigation on the lightwave signal in one loop of the gyro system was conducted.According to the expansion of phase modulation spectrum and optical field overlapping method,the transmission characteristics of fiber ring resonator were analyzed.The carrier component could introduce backscattering noise in the gyro system.The amplitudes of carrier component were simulated and analyzed,which showed that triangular wave modulation was superior to sinusoidal wave modulation.To suppress carrier component,the self-heterodyne carrier suppressed system was set up.The triangular wave and sinusoidal wave were applied to the phase modulator,respectively.The experiments show that carrier suppressed ratio of triangular wave modulation could reach 64.3 dB,which is 6 dB higher than sinusoidal wave modulation.The experimental results are consistent with the theory.Applied to the gyro system,carrier suppressed degree of the output signal is bigger,the fluctuation is smaller,and the gyro output is more stable using triangle wave modulation.

The influence of Compton scattering on the modulation instability near zero dispersion in plasma is studied by using the model of multi-photon nonlinear Compton scattering and nonlinear Schrdinger′s equation, a new mechanism on the modulation instability is formed by Compton scattering has been raised, a amended dispersion equation on the light pulse propagation has been given out, and it is simulated with the numbers. The results show that when the second-step dispersion is bigger,the gain score of the modulation instability of the wander from the nearby zero dispersion is decided by the second-step dispersion produced by incident and scattered lights. The fourth-step dispersion effect is quickly decreased along with the increasing of the second-step dispersion,and the cause is that the fourth-step dispersion effect is affectively weakened by Compton scattering. The gain score of the modulation instability near the zero dispersion is decided by the fourth-step dispersion produced by incident light and scattered light, the second-step dispersion is annihilated,the maximum number of the perturbation frequency is quickly approached to critical perturbation frequency, and the cause is that the fourth-step dispersion effect is affectively increased by Compton scattering. The width of the gain score is quickly increased along with the increasing of the plasma loss, the cause is that the scattered effect is increased along with the power increasing, and the effect causes that the radiation damping of the charged particle is increased.

Airborne ocean colour remote sensing urgently require wide angle and large relative-aperture hyperspectral imager.Based on the research objective of wide angle and large relative-aperture,an airborne hyperspectral imager optical system was designed using an off-axis two-mirror anastigmat telescope and a modified Offner spectrometer.The field of view of hyperspectral imager was 40°,relative-aperture was 1/2.2,and working waveband was from 0.4 μm to 1μm.Relative aperture and image quality were improved by inserting a concentric meniscus in a classical Offner spectrometer.Ray tracing,optimization and analysis were performed by ZEMAX software.The analyzed results demonstrate that the MTF for different wavelengths is more than 0.67 at Nyquist spatial frequency 28 lp/mm,both smile and keystone are less than 6.5% of the size of pixel.It is easy for spectral and radiation calibration.The design results satisfy the requirements of specifications,the volume is small,mass is low,and is suitable for airborne remote sensing.

Imaging technology based on Panoramic Annular Lens (PAL) is the most potenial imaging method,PAL-based imaging system with long focus and high resolution has complicated optical structure,structural design is the primary problem.On the basis of optical path structure and imaging properties of the PAL-based imaging system,the design method of PAL and realy lens was discussed in detail,single PAL and complicated PAL were modeled,the aberration characteristics between them were compared,and the optical path connection condition and aberration compensation project between them was analysed.In this design,image was received by CCD with small size through off-axis scanning,meanwhile,the feasibility of the scanning mechanism was stated.According to the requirement of distinguishing 250 mm object at 300 m,system focus and CCD type were chosen reasonably by calculating,and a set of technical parameters were determined.A high resolution PAL-based imaging system whose focal length was 8 mm,relative aperture is F/# 3.2,lateral field is 40°~100° has been designed finally,which consisted of three agglutination PAL and relay lens of 8 pieces and 6 groups,all surfaces were spherical and all field MTF at 80 lp/mm were higher than 0.5,illumination uniformity of image was higher than 0.95,f-θ distortion of all field was within ±3%.the design meets the usage requriement well.

To overcome the problems of the present grating spectrometer, such as low resolution, large aberration, and large size, a kind of Czerny-Turner spectrometer optical system whose effective wavelength range is from 350 nm to 450 nm was designed based on the working princle spectrometers and the aberration theory. Parameters of the optical elements and structure were calculated. The ray tracing, simulation and optimization for the optical system were carried out with optical design Zemax software. The theoretical and experimental results demonstrate that the optical system can operate in 350～450 nm waveband with resolution less than 0.1 nm. The optical system size was 105mm×105 mm×20 mm, it is characterized by simple structure, small size, high spectral resolution, and good stability.

In order to meet the demand that unobscured three-mirror optical systems should be small volume with excellent optical performance,a circular three-mirror optical system was proposed.A coaxial three-mirror system is calculated by the paraxial matrix as a starting point.With the condition that the focal point of each conic mirror is placed to coincide successively,elements in the system are tilted and decentered properly to make the system unobscured and to fold the optical path in the region surrounded by three mirrors to reduce the system volume.Zernike polynomial surfaces which are symmetric about tangential plane are used to correct aberrations and to improve the image quality.An uncooled long wave infrared optical system is designed at focal length 310mm,F-number 1.55 with field of view 1.774°×1.331°.The modulation transfer function of this system is above 0.52 all over the field of view at the Nyquist frequency of 20 line pairs per millimeter.

In order to meet wide-field,high image quality and easy portability of infrared detection equipments,a large field transmissive infrared collimator system with working band of 8~14 μm,full field ≥24 °,aperture of 130mm was designed.A simple three-type telephoto lens structure and a non-spherical were used to solve the problem that how to balance the three transmission systems aberration.According to the theory of optical design optimization of multi-level system design,eventually a infrared transmissive collimator system was obtained, the MTF at 20 lp/mm was not less than 20%,distortion resolution rate infinity was less than 1% in the whole field of view and the position of each focal length corresponding to different wavelengths.The advantages are wide field of view,high resolution,good image quality and simple structure,which can provide high image quality,high-resolution infrared target source at infinity for a variety of infrared imaging,military infrared detection system performance parameters sights.A prototype application was developed and applied to verify alignment test.The results show that the prototype can get clear and accurate images to meet testing requirements.

The omni-directional transmission (reflection) properties were theoretically investigated for photonic heterostructures composed of cascaded one-dimensional photonic crystals. Each photonic crystal in the structure has the same materials and different optical thickness ratios of the alternate high-and low-refractive index layers. Taking two photonic crystals cascaded structure as the object of study, the change of photonic bandgap with different polarization and incident angle was investigated through transfer matrix method, the condition of designing omnidirectional reflectors with the maximum photonic bandgap width was obtained, i.e., the upper bandgap edge of the former photonic crystal overlaps with the lower bandgap edge of the latter photonic crystal at the maximum incident angle. The parameters of the omnidirectional photonic bandgap were given for the cascaded structure with the condition satisfied and not satisfied. The widths of the omnidirectional photonic bandgap were compared. The results show that the cascaded structure with the condition satisfied has the maximum omnidirectional photonic bandgap width.

The model of floated sphere in the triode configuration was proposed and the actual electric field and the field enhancement factor at the top of carbon nanotube were calculated analytically by superposition principle of electric field. The effects of the contact resistance, the geometrical parameters of device, and the dielectric of between the gate and cathode were computed. The calculation results show that the emission current from carbon nanotube is greatly reduced by the contact resistance. When the contact resistance is larger than 100 kΩ, the emission current from carbon nanotube tends to be zero. The field enhancement factor was at a maximum value under the condition of the vacuum. The gate-hole radius, the gate-cathode distance, and the gate-anode distance greatly affect the field emission properties of the device. The field emission properties improved via optimizing the parameters above mentioned and modulating the gate voltage.

The 4×4 transfer matrix method was used to investigate the optical isolation property of two different one-dimensional magneto-photonic crystal structures. For the first structure, when the angle between applied magnetic field and optical axis was set as 52.0°, it could realize the optical isolation around 0.95 nm with total thickness of 7.96 μm, possesses Faraday rotation angle and transmittance wave were at 45°~50.65° and 97.01%~99.96%. This structure with 43 layers is applicable in the practical application and fabrication. Regarding the other structure, when the angle between applied magnetic field and optical axis was set as 32.7°, optical isolation reached 0.85 nm broad with total thickness of 11.54 μm, the Faraday rotation angle fluctuated from 45.0°~48.55° and the transmittance ranged from 98.85%~100%. Integrable optical isolators can be accessed by using the two proposed one-dimensional magneto-photonic crystal structures instead of the bulk type magneto-optical materials in bulk type optical isolator in commerce.

The Oxygen absorption characteristic was analyzed and four hyperspectral sensor models were built with full width at half maximum of 15, 10, 5 and 2.5 nm. Four spectral matching styles and six spectral matching algorithms were proposed. The measured spectrum and referenced spectrum with spectral offset were simulated based on MODTRAN radiative transfer model. The spectral calibrations of hyperspectral sensor with different FWHMs were processed using four spectral matching styles and six spectral matching algorithms. Then the in-flight spectral calibration accuracy was analyzed quantitatively. The results show that the spectral calibration based on correlative coefficient of measured apparent radiance and referenced apparent radiance has the highest accuracy.

Synthetic aperture ladar can work with low pulse repetition frequency and obtain wide scene with muti-channel in terrain observation by progressive scans mode.However,the frequency spectrum in azimuth of the raw data in each channel is ambiguous,which ambiguity can not be removed by conventional spactial beamforming.To solve this problem,a novel method of spactial beamforming based on spectral compressing was proposed.Firstly,a transformation in azimuth was introduced with deramp technology.Then,spactial beamforming was used to remove the ambiguity.Thirdly,a phase factor was used to compensate the phase error induced by the deramp.Finally,a conventional imaging algorithm can be used to abtain images from unambiguous data.The imaging experiment with numerical data validates the feasibility and effectiveness of the proposed method.