Abstract:The study on As 4-doped HgCdTe epilayers grown by MBE was presented. The electrical activation of arsenic impurities was achieved by annealing that caused As to occupy Te sites. By using the secondary ion mass spectrometry (SIMS) and Hall measurements on the in situ arsenic doped HgCdTe epilayers, the results show that P-type MBE HgCdTe can be obtained by doping with As 4 source and annealing with high temperature.

Abstract:测量了ZnS:Mn纳米粒子以及相应体材料在不同压力下的光致发光谱.随压力增大,来源于Mn2+离子的4T1 6A1 跃迁的桔黄色发光明显红移.体材料和 10, 4. 5, 3. 5, 3nm的ZnS:Mn纳米粒子中Mn2+发光的压力系数分别是-29. 4±0. 3和-30. 1±0. 3, -33. 3±0. 6, -34. 6±0. 8, -39±1meV/GPa,压力系数的绝对值随粒子尺寸减小而增大,该种尺寸关系由晶体场场强Dq和Racah参数B值的尺寸依赖性引起. 1nm样品的Mn2+发光的特殊压力行为是因为样品的粒子尺寸比较小,另外,分布在Y型沸石中的纳米粒子的表面状况也不同于其它样品.

Abstract:采用Huybrechts的线性组合算符法和改进的LLP变分法，研究了晶格热振动对无限势垒量子阱中电子与界面光学声子强耦合、与体纵光学声子弱耦合极化子性质的影响．推导出作为阱宽和温度函数的极化子自陷能的表达式．对KI／AgCl／KI量子阱进行了数值计算，结果表明，极化子的自陷能随阱宽增加而减小、随温度升高而减小，但不同支声子与电子相互作用对极化子自陷能的贡献以及它们随阱宽和温度的变化情况大不相同．

Abstract:VO ~2-x nanopowders were successfully synthesized with different oxygen content. The effects of oxygen content on the crystal lattice and phase transition properties were obtained form the experiment. Our result shows that vanadium interstitials are formed in oxygen-deficient samples, while oxygen interstitials are formed in the samples with excess oxygen. Both factors result in the expansion of the volume in the crystal unit cell. And the defects induce anisotropy in the lattice, which is observed in the deformation of the crystal grains with different oxygen content. The redistribution of electronic strucure in the energy band may be one of the factors that result in the changes of phase transition properties in VO ~2-x.

Abstract:The response peak wavelength of a quantum well infrared detector was predicted directly by measuring Raman spectrum of multiquantum well materials. It no longer requires preparing infrared detector or polishing on the edge of sample. Therefore, this method is simple and reliable.

Abstract:The research of infrared radiation characteristics of high temperature free-stream flow with particles is very important for the field of target detection, combustion diagnosis and temperature measurement of flame. In this study the infrared radiation characteristics of high temperature free-stream flow were calculated with backward Monte-Carlo method. The effect of the particle scattering and different boundary conditions on the directional radiation heat flux was examined. The calculation results were compared with forward Monte-Carlo method. The result shows the superiority in computational efficiency of backward Monte-Carlo method.

Abstract:多层介质反射镜在非正入射的时候,两个不同的偏振态之间会产生不同的相移.根据空气与膜层、膜层之间的实际情况,建立了界面层和表面吸附层模型,并运用它分析相位延迟产生误差的原因.通过优化设计,入射角为 54°,在 1285~1345nm之间p,s波获得了 270±1°的相移,同时也使反射率在 99. 5%以上.用离子束溅射技术制备相位延迟膜,用分光光度计测试了光谱特性和用椭偏仪测试了相位特性,在相应波段获得了 262. 4±1. 8°的相移,同时也使反射率在 99. 6%以上.误差的主要来源是离子源工作特性会产生不均匀的过渡层和最外层会吸收一些水汽、灰尘等也产生表面过渡层.由误差分析得出了制备中过渡层的物理厚度和折射率的变化情况,最外层的厚度误差和折射率偏差是发生相移偏小的主要因素.

Abstract:为了在抑制噪声时尽可能保留图像边缘信息，提出一种自适应各向异性高斯滤波器设计方法．该方法由独立强度传播(IDS)模型决定滤波器的长轴尺度，由像素的邻域平滑度决定长短轴的比例，然后根据该处的灰度梯度方向自适应决定各向异性滤波器的长轴方向．仿真实验表明，提出的自适应各向异性滤波器具有很强的噪声抑制和边缘保持能力．

Abstract:An effective aproach based on normalized cuts to segment infrared object was presented. The method is related to the graph theory. An image was represented as a weighted undirected graph, where the nodes of the graph were the pixels of the image, and an edge was formed between every pair of pixels. The weight on each edge was function of the similarity between the two pixels, and the similarity was related to the gray level and the position of pixels. Normalized cut was chosen as the principle to distingusish object from background. The time and space complexity of the algorithm was studied. Four kinds of domain-weight-matrix were defined and a quick table-search method was presented to improve the real-time algorithm. The experimental results show that the proposed method has excellence performance, and it is superior to the traditional segmentation method.

Abstract:为有效地判别和剔除红外焦平面阵列(IRFPA)的无效像元，本文在分析了IRFPA有效像元响应模型的基础上，指出在均匀输入时IRFPA有效像元输出值的均值差(DOM)和标准差(STD)特征的分布具有正态性。通过采用自适应投影匹配分解法对特征直方图进行高斯分解，进而估计出有效像元DOM和STD特征的分布区间，从而得到了判别无效像元的分类准则．针对实际IRFPA图像数据的实验表明，本文提出的无效像元的判别方法是有效的．

Abstract:A series of mode experiments for the infrared signature suppression (IRSS) device used in the helicopter gas turbine exhaust system were carried out to investigate the effects of ambient air pumping-mixing and heat shelter-insulation on decreasing the target infrared signature and quest for the infrared signature similarity between two scaled models with different scale factors. The results show that (1) Ambient air pumping-mixing plays a dual role for reducing the exhaust temperature and mixing duct temperature and this role is more obvious in the case of larger mass flow ratio of secondary flow to primary flow. Sheltering from the hot mixing duct wall makes the sheltering sheath temperature close to ambient temperature in case of the sheltering distance greater than 20mm. (2) Ambient air pumping-mixing contributes about 85% suppression for the total target infrared radiation intensity and heat shelter-insulation contributes about 10% suppression again. (3) While the primary flow velocity, temperature and pressure are at the same condition for different scaled models, the irradiances for different scaled models are almost the same and the infrared radiation intensity is almost proportion to the square of model scale factor.

Abstract:A regularized restoration algorithm based on maximum-likelihood estimation was presented for restoring object images from the noisy turbulence-degraded images. The logarithmic maximum-likelihood function for multi-frame image data based on the model of image random field was built, and some auxiliary terms to smooth noise while preserve the edges of images and the penalized item to avoid trivial solutions were added to the maximum-likelihood function. The iterative formulas of calculating the PSFs and object image were derived so that the PSFs and the object image could be estimated in the iterative manner. A parallel processing scheme for the algorithm is also proposed.The restoration experiments on the simulated turbulence-degraded images in the case of noise show that the proposed algorithm has high ability of noise-resisting and it has some practical applications.

Abstract:A new image retrieval algorithm based on image entropy and spatial distribution entropy was presented. At first a more robust method, which can remove the influence of the symmetry of entropy, was proposed to extract the global color feature. Then color spatial distribution entropy vector for each color channel was also introduced to represent the spatial color information. After that, the moments were adopted to reduce the dimension of color spatial distribution entropy. In the end, a low dimensional vector which includes the global and spatial information was used as index for color image retrieval. The experiment results show that the new method gives better performance than color histogram.

Abstract:The zero-bias resistance area product (R 0A) and the saturation current density J 0 are both key parameters to give an indication of photodiode performance. In this study, an effectual experimental method to study the minority carrier diffusion characteristics of Hg ~1-xCd xTe photodiodes was presented. By I-V tests in a variational magnetic field B, R 0A and J 0 measurements were carried out as a function of B in the alloy composition range 0.5

Abstract:采用ICP刻蚀的方法,在SOI材料上制作出了中心波长为 1. 5509μm、信道间隔为 200GHz的 5×5阵列波导光栅(AWG).测试中心波长与设计值相差 0. 28nm,测试波长间隔与设计值相差在 0. 02nm之内,相邻信道串扰接近10dB,信道插入损耗均匀性为 0. 7dB,测试结果表明该器件能够初步达到分波功能.

Abstract:For effective detection of foreign fibers which have almost the same shape and color as the cotton fibers, an infrared spectral imaging method based on the absorption characteristic discrimination between cotton fibers and foreign fibers was proposed. According to the method, the relation between the absorption characteristic discrimination and the wavelength in the region of near infrared was analyzed, and the optimal band for discriminating several types of foreign fibers from cotton fibers was determined. The absorption characteristic of foreign fibers was transformed into the image feature in the infrared spectral imaging system. Furthermore, the foreign fibers were extracted form the background of lint by using adaptive image enhancement and binary image processing. The experimental result indicates that the image features of foreign fibers are obvious. And it provides an effective method to detect foreign fibers in lint.

Abstract:A novel stationary multiwavelet transform (SMWT) method was proposed. The method possesses the good quality of both multiwavelet transform and stationary scalar wavelet on signal denoising. The mallat decompositing and reconstructing of 2D image based on SMWT was inferred. By thresholding the SMWT coefficients of noisy infrared image, the original image can be reconstructed. The simulation results show that the image denoising effect of this method has obvious superiority compared with scalar wavelet and general multiwavelet transform method. At the same time, the reconstructing image can preserve the characterisics of original image as many as possible.

Abstract:根据已提出的二维周期介质严格理论，比较详细地分析和研究了介质波导阵列的电磁特性．首先，对存在纵向波传播时(kz≠0)的空间谐波相互作用特征进行了分析，得出了横向波传播色散特性．其次，在横向平面上的两互相垂直方向的波数相等(kx=ky)时，对不同波频率下空间谐波相互作用特性及其产生的阻带分布特征作了详细研究，并对横向纵向波传播色散关系进行了分析和计算．最后，得出介质波导阵列存在纯纵向导波的十分有意义的结论，具有实用价值．