Abstract:The Raman spectra of MBE-grown GaAs_(1-x)Sb_x in a relatively wide range of composition are reported for the first time. It is observed that the frequency shift of phonons strongly depends on the composition x of Sb. The two-mode behavior of optical phonons is observed only when the composition x of Sb is larger than 0.15. This result is confirmed by the reflectance spectra measured by using a Fourier transform spectrometer. The analysis of GaAs-like LO lineshape shows that the MBE-grown GaAs_(1-x)Sb_x material used in this work has good quality. The experimen tal results are discussed by using the mass defect model and percolation theory.

Abstract:报道N型含氮直拉硅单晶的光热电离光谱(PTIS)除观察到P的谱线系列外,还观察到三个与氮、氧有关的复合型浅施主中心D(N-O)的谱线系,首次报道了它们3p_±以上的谱线位置,并精确测定了其电离能为36.16meV、36.41meV和37.37meV。变温分析表明,它们不是源于同一化学中心的基态分裂,而是独立的复合施主中心。

Abstract:对掺Sm的CdTe(CdTe:Sm)晶体的红外光谱(400～5000cm~(-1))研究表明其中存在Sm~(2+)和Sm~(3+)两种价态的Sm离子,Sm~(2+)处于晶体的间隙位置,周围为非立方对称的晶体场;Sm~(3+)可以取代Cd原子而位于晶格格点处(C中心),也可以处于晶格间隙位置依其次近邻是否存在Cd空位而分别构成A中心和B中心。B中心和C中心均处于立方对称的晶体场中,经退火(Cd气氛,～600°)A中心消失。

Abstract:测量了掺Fe浓度为1.5×10~(18)～7×10~(19)cm~(-3)的HgSe:Fe样品在中红外波段内的室温透过率和反射率,由此看出Fe浓度大于或小于4×10~(18)cm~(-3)时吸收系数,迁移率和吸收截面的性质明显不同,用Fe的空间有序化模型解释了实验结果。

Abstract:The design and consideration of an optical coherent two-wave coupling and a self-pumped phase conjugator using totally internal reflection in the photorefractive KNbO_3: Fe are reported. The exceptionally large value of the electro-optical coefficient r_(42) and an optimized geometrical configuration are considered for both cases. The nature of phase conjugation of the retroreflected beam ls demonstrated. Nonlinear optical effects are extended successfully from wavelengths 514.5nm to 632.8nm.

Abstract:The calculation method of self-absorption in the theory of optically pumped far infrared lasers is proposed in this paper. In addition, a revision term, which is related to the operating gas pressure, is discovered. By this term the theoretical calculation results are in good agreement with the experiments.

Abstract:A model of two-layer neural network with orthogonalized storage is proposed. A system based on the model will have a capability of both auto-associative and hetero-associative memories. Monte Carlo simulation shows that the maximum number of stored key patterns with the model can he up to N(the number of neurons in each layer of the network) and a good content-addressability is achieved.

Abstract:Frequency characteristics of photothermal signals on the front and rear surfaces are discussed for various cases. The experimental results and relevant discussion of some optically opaque samples are given.

Abstract:用完整的热成象系统灵敏度方程,研究了高灵敏红外测温仪(红外辐射计)用于双园筒法测量物体比辐射率时,其噪声等效反射率差NE△ρ与噪声等效温差NETD的关系。对《风云一号》气象卫星辐射致冷器辐射定标用的蜂窝平面黑体源的比辐射率ε进行了测试,其结果与用Gouffe公式及能量选加原理对蜂窝面源平均比辐射率的计算值吻合得很好。指出了提高蜂窝面源比辐射率的有效方法。

Abstract:The iridium silicide-silicon Schottky barrier has been fabricated and the diffraction spectra of samples are analyzed. The formation process of iridium silicide and the relation between the process and square resistance of the film are discussed. Schottky barrier height and infrared absorptivity are measured and analyzed. The results show that the iridium silicide-silicon barrier is a new type of structure expected to be used in detecting infrared radiation extended to longer wavelengths.