Abstract:The complex refractive index of smalll particles is determined from the transmittance spectrum by the use of the Simplified Mie scattering theory and Kramers-Kronig relation. The numerical simulation results for the soot particles with relatively large size show that this method is simple as compared with the existing method. The accuracy of this method is improved and the ranges of wavelength and particle size are expanded. At last the transmittance spectrum of the coal particle cloud is measured by an Infrared spectrometer and its complex refractive index is determined.

Abstract:A high-precision optical fiber transmission system used for multiple-path test signals in a special test system and its principle of operation, design, structure and the results in practical experiments are described. A formula which is used to calculate the required sample rate for the system of high precision is given.

Abstract:From the viewpoint of real-time application, the MADALINE network for invariant feature extraction is improved. Presented are the algorithm structure for the MADALINE invariant network with local interconnection, which is simplified to usual matrix computation, and the approaches by learning to determine the adaptive MAJ threshold and the fixed MAJ threshold. The improved network with local interconnection is implemented for binary patterns. The comparisons of MADALINE with its improved version are made.

Abstract:The GaAs/GaAlAs heterojunctions with different thicknesses of cap layer were investigated by the use of photoreflectance (PR) spectroscopy. By analyzing the Franz-Keldysh Oscillation (FKO) in PR spectrum, it was found that the thickness of cap layer would influence the surface band structure of heterojunction, and the surface field was increased with the decrease of thickness of cap layer. It was also found that the PR lineshape would rotate with the varying of the thickness of cap layer. This is coincident with the theoretical calculation while considering the interference effect between different layers.

Abstract:Infrared transmission measurements were made to investigate the influence of hydrogen passivation on Hg_(1-x)Cd_xTe wafers. It was observed that, after boiling the samples in water, the infrared transmittance increased, the absorption edge was moved to the short wave direction and the absorption below the energy gap was reduced, and that the range of infrared transmission was narrowed. Through calculating the trans-mittance of Hg_(1-x)Cd_xTe with the multiple layer model, it was found that hydrogen passivation influences not only the surface but the whole bulk of Hg_(1-x)Cd_xTe wafer. Careful analyses showed that, the changes of Hg_(1-x)Cd_xTe infrared transmission spectrum after hydrogen passivation are the results of the effective passivation of residual impurities or defects, the reduction of carrier concentration, the increase of composition x, the effect of local internal electric field of charged impurities or defects, and the enhancement of scattering of charged impurities or defects.

Abstract:Electrical measurements (DLTS and C-V) were combined with surface analysis techniques (AES and SIMS) to study the reactions, atomic structure, the distribution of defect/impurity and the Schottky barrier heights at Pt/Si and Pt-silicides/Si interfaces. The relation between the interracial reaction and the formation of Schottky barriers is discussed in this paper in detail.

Abstract:研制了不同厚度的ＰＶＤＦ：ＴＧＳ复合膜，实验结果表明：膜越薄，其介电常数，介电常数，介电损耗和热释电系数越大，对实验结果做了定性解释。研制了复合薄膜探测器，其Ｄ＊（５００Ｋ，１２．５Ｈｚ）达１．５５×１０＾８ｃｍ．Ｈｚ１／２．Ｗ－１。

Abstract:报道了聚合物DR/PMMA薄膜材料的红外光学特性及由薄膜材料形成法—珀腔结构的透射率随外加电压的变化规律,测定了折射率的色散n(λ)、三阶极化率χ~((3))(-ω;ω,0,0)和二次电光系数(kerr系数)R,在室温下测得波长为792.4 nm时χ~((3))=(2.0-i0.32)×10~(-11)esu,R=-(4.9-i7.9)×10~(-20)m~2/V~2。