Abstract:As the infrared technology continues to advance, there is a growing demand for multispectral detectors for advanced IR systems with better target discrimination and identification. Both HgCdTe detectors and quantum well GaAs/AlGaAs photodetectors offer wavelength flexibility from medium wavelength to very long wavelength and multicolor capability in these regions. The main challenges facing all multicolor devices are more complicated device structtures, thicker and multilayer material growth, and more difficult device fabrication, especially when the array size gets larger and pixel size gets smaller. In the paper recent progress in development of two-color HgCdTe photodiodes and quantum well infrared photodetectors is presented.More attention is devoted to HgCdTe detectors. The two-color detector arrays are based upon an n-P-N (the capital letters mean the materials with larger bandgap energy) HgCdTe triple layer heterojunction design. Vertically stacking the two p-n junctions permits incorporation of both detectros into a single pixel. Both sequential mode and simultaneous mode detectors are fabricated. The mode of detection is determined by the fabrication process of the multilayer materials.Also the performances of stacked multicolor QWIPs detectors are presented. For multicolor arrays, QWIP's narrow band spectrum is an advantage, resulting in low spectral crosstalk. The major challenge for QWIP is developing broadband or multicolor optical coupling structures that permit efficient absorption of all required spectral bands.

Abstract:The polarization characteristics of electroluminescent polymers were studied with the theoretical model including the external field, electron-electron and electron-lattice interactions simultaneously. It was discovered that on-site Hubbard energy and the nearest neighbor electron-electron interactions increase the negative polarization of self-trapping bi-excitons in polymers obviously. The physical significance of negative polarization-a new phenomenon, and its possible applications were also explored.

Abstract:用磁控反应溅射（ＲＳ）法制备出ＧｅｘＣ１－ｘ薄膜，它的折射率可在１．６～４．０之间变化，设计出没厚度的ＧｅｘＣ１－ｘ均匀增透膜 非均匀增透膜系，并在ＺｎＳ基片上制备出ＧｅｘＣ１－ｘ均匀增膜系，设计结果表明，均匀膜系实现某－波段范围内增透，非均匀膜系能实现宽波段增透；当厚度增加时，均匀增透膜系的透过率曲线变得急剧振荡，非均匀膜系的透过率曲线变得更为平滑，且向长波段扩展，实现结果表明，在８～１１．５μ

Abstract:提出一种新型GaAs/GaAlAs子带间光吸收的红外光电导探测机理,利用MOCVD系统进行器件材料的生长,研制了200μm×200μm的台面形式单管,测到了明显的红外光电流信号及阱间共振遂穿效应造成的负阻震荡现象,对器件的性能测试结果表明,器件的光电流响应和信噪比随着阱数增加而增加,器件噪声比常规GaAs/GaAlAs量子阱红外探测器低一个数量级.

Abstract:用ＯＭＩＳ－Ⅱ航空成像光谱仪在有地区进行了地表遥感实验，研究了ＯＭＩＳ－Ⅱ波段反射比Ｒ（２１）／Ｒ（１８）与藻类叶绿素浓度的关系，由ＯＭＩＳ－Ⅱ遥感图像估算了研究区域内发素浓度分布，并将遥感估算值与地面采样数据进行了比较。结果表明，ＯＭＩＳ－Ⅱ能够提高藻类叶绿素定量遥感的精度。

Abstract:A GaAs transmission photocathode structure was prepared.The variations of the cathode photosensitivity and mean transverse energy through the course of typical activations were measured systematically in the photocathode activation and imaging system. The GaAs(Cs,O) photocathode surface was examined by scanning electron microscope. It was concluded that the transverse energy of photoelectrons emitted from GaAs(Cs,O) photocathodes, which is largely independent of the (Cs,O) activation layer, is determined by the GaAs lattice temperature, photocathode surface roughness and multiple scattering processes in the band bending region.

Abstract:用二次离子质谱（ＳＩＭＳ）分析了低能注放（１５０ｋｅＶ）砷在体材料碲镉汞中的分布和注入砷原子在碲镉汞中的热扩散情况，砷在碲镉汞中的分布表现出复杂的多元扩散机制。在缺陷密度（ＥＰＤ）比较低的碲镉汞材料中，砷扩散的主体符合恒定扩散系数的有限源扩散模型，呈现出浓度随深度的高斯分布。而在缺陷密度比较大的碲镉汞材料中，砷的分布呈多段指数型分布，表面出更复杂的多机制扩散特性。

Abstract:One dimensional equation of heat conduction, its initial conditions and boundary conditions were described. The surface temperature difference between the flawed and the unflawed regions was given. The surface temperature difference versus heating time, delamination thickness in bonding silicon wafers containing delamination was calculated. The experiment was carried out by using an infrared thermal imager.

Abstract:The characteristics of low light level (LLL) image were analyzed in aspects of imaging process gray level distribution and correlativity of picture element in space and time of LLL image. Richness of gray level of highly correlative image was expressed using information capacity,which agrees greatly with the effect of vision evaluation.It is of momentous guidable significance for study on LLL multi spectrum image fusion technology by analyzing these characteristics.

Abstract:A new structure using increased width waveguide to realize E plane filters was proposed and it has been able to reach wide bandwidth. The bandwidth of 4GHz can be realized at the low frequency end in the Ka band and this can satisfy the requirements of full band multi channel frequency branching. The design theory was presented, and computer simulation and experimental results were given to show the feasibility of the new structure and the validity of the analysis and design method.

Abstract:The improved genetic algorithm was applied to the optimization design of high performance millimeter wave diplexers. The waveguide H plane junctions and the E plane septum filters were used for designing the diplexers. The genetic algorithm was used to optimize the diplexer including optimizing the filters and the structural parameters of the diplexer itself. Three diplexers of different frequency bands were designed accoding to this method.One diplexer of millimeter wave band was designed and fabricated. The agreement between the theoretical and the experimental results of a millimeter wave diplexer proved the accuracy and validity of the genetic algorithm.

Abstract:A novel range profile identification system based on multiple classification was discussed. After feature compression with K L transform, one can get a rough identification result by clustering or eliminate impossible candidates according to some rules. The remainder is identified by fuzzy ARTMAP neural network with the feature extraction of the optimal set based on the Fisher criterion. The experiment shows that this classifying method could be more effective than the single classifier method.

Abstract:The problem of detecting targets in the cluttered circumstance with millimeter wave high resolution radar was studied. A new idea of improving SCR(Signal to Clutter Ratio) was presented by nonlinearly weighted integration in polarization domain. A polarization target detection method was then presented based on the range position correlation of one dimensional range profile of high resolution radar target. Experimental results show that this kind of detection strategy is quite effective for extended targets.

Abstract:A new waveform utilizing Costas sequence and interpulse frequency hopping (FH) can be used as a good high range resolution radar signal. The signal processing using inverse discrete Fourier transform (IDFT) in the interpulse Costas FH radar was studied. The principle of the interpulse Costas FH radar signal without the delay Doppler coupling was analyzed. The influence of target motion on synthetic range profile was discussed and simulated.

Abstract:Based on the normalization principle of reflectivity and emissivity of millimeter wave stealth material with its transmissivity being neglected, a new method was proposed to test the reflectivity and emissivity of wave absorbing material using a MMW scanning radiometer. The formula of calculation of this method was derived, in addition, some results of the testing were given.