锥形光纤中光波传输特性的蒙特卡罗模拟

为了分析锥形光纤中光子流的传输特性和空间分布特性，采用了蒙特卡罗算法对其进行了模拟仿真，得到了大量光子经过锥形光纤后的光子分布图.模拟实验结果表明，通过锥形光纤的大量光子集中在探测器中心，到达探测器某一位置的光子数随着该位置到探测器中心距离的增加而减少，并且在锥形光纤锥度比一定的条件下，改变锥形光纤长度，光强度随着长度的增加而下降，但通过锥形光纤的光子分布是一样的.这些研究结果对锥形光纤的设计和实际应用提供了重要依据.     

Negative luminescence in semiconductors: a retrospective view

Twenty-five years ago, we introduced the phenomenon of negative luminescence (NL) into semiconductor physics. This paper provides an overview of work conducted to develop this fundamental concept. Initially, we consider the first-principle approach to radiation interaction with basic matter and the major properties of NL. Then we describe the problems of NL direct measurements in homogeneous materials and structures. Finally, we emphasize the use of NL approach in applications involving devices for infrared (IR) wavelength (3–12 μm) high-temperature (300–400 K) optoelectronics. Our subjects will include NL IR emitting diodes, radiative coolers, IR dynamic scene simulators, light up-conversion devices, and the Stealth effect in IR.     

光放大器前置可调光学滤波器

介绍Ｆ－Ｐ干涉滤波器实现中心波长可调的两种机理，给出通过改变腔距来改变中心波工的滤波器的典型结构，并且给出了相应的电压驱动电路，实验表明选择合适的光放大器前置滤波器可以提高系统的灵敏度。     

星载光学系统遮光罩消杂光结构优化设计方法

本文对星载光学系统遮光罩消杂光结构的优化设计做了初步探讨。提出了遮光罩和挡光环消杂光设计的基本原则。给出了一种二级遮光罩结构寸的优化设计方法和一种遮光罩内壁上挡光环位置优化设计方法,并对一级和二级遮光罩进行了初步的分析比较。     

环境光对PE塑料薄膜近红外激光拉曼光谱的影响

探讨了环境光自然光和室内荧光灯光的存在,对PE透明塑料薄膜的近红外激光拉曼光谱的影响.研究表明不同的环境光,会对近红外拉曼光谱产生不同的明显特征峰.自然光干扰产生的是以倒峰群形式为主,而室内荧光灯光造成的干扰主要以尖锐的脉冲峰形式.虽干扰表现形式不同,但都有严重地影响,在测定时一定要引起重视,不能忽略.建议在进行透明塑料近红外拉曼光谱检测时,须在暗室或暗罩遮光保护中进行,以完全隔离环境光的影响.     

自控液晶光阀组式光刻快门研究

通过理论推导，构建了抗蚀剂的感光特性、光源的光效与曝光量之间的数学模型，为液晶光阀代替穿孔带提供了理论依据.结合液晶光阀的工作原理和光刻快门的控制原理，对液晶光阀组的控制进行了研究并给出了其控制电路图.通过实际光刻试验，自控液晶光阀组光刻快门机构可以完成编码图案的控制，通光控制达到了预计要求，刻出的图案清晰，线条陡直.证明液晶光阀组替代穿孔带用作光刻快门是完全可行的.     

流-固界面波的激光激发与光偏转检测

基于光偏转原理,研制了可用于流-固界面波探测的光纤传感装置.在此基础上,建立了以调Q Nd∶YAG激光为流-固界面波激发光源的实验系统.实验上探测了激光在空气-铝、水-铝和酒精-铝等界面上激发的界面波波形.根据实验波形,算得在这三种界面上的泄漏Rayleigh波和Scholte波的速度分别为2889 m/s和339 m/s、2916 m/s和1512 m/s、2872 m/s和1184 m/s,此实验值与理论计算值相比,偏差小于5％.     

Determination of the boiling point distribution of sulfur compounds in light cycle oil using GC with a flame photometric detector and pyrolyzer

A method has been developed to determine the boiling point distribution of sulfur compounds in light cycle oils (LCO'S). The method chosen for this analysis was GC with a flame photometric detector (FPD) and pyrolyzer. Tests were carried out to evaluate the recovery efficiency, repeatability, and accuracy of the method. Repeatabilities within 2% were obtained. The recovery of benzothiophenes and dibenzothiophenes was close to 100%; this was important because these are the major sulfur components in LCO's. No hydrocarbon or solvent interferences were observed with the use of the pyrolyzer, even for a 95% solvent level. Comparison with results from other techniques showed that the method accurately determined the levels of sulfur compounds in the LCO boiling point range.     

Resonant-cavity-enhanced photodetectors and LEDs in the mid-infrared

In this paper we outline the use of resonant-cavity enhancement for increasing the exterior coupling efficiency of photodetectors and light-emitting diodes (LEDs) in the mid-infrared (MIR) spectral region. This method is potentially very important in the MIR because encapsulation is not presently feasible due to the lack of suitable materials. Among other potential applications, resonant-cavity-enhanced (RCE) photodetectors and LEDs could be particularly suitable for greenhouse gas detection because of their ‘pre-tunable’ spectrally narrowed resonantly enhanced peaks. We also present the optical characterization of an InAs RCE photodetector aimed at the detection of methane gas (λ≈3.3 μm), and an InAs/InAs_0.91Sb_0.09 resonant-cavity LED (RCLED) aimed at carbon dioxide gas (λ≈4.2 μm). The high peak responsivity of the RCE photodetector was 34.7 A/W at λ=3.14 μm, and the RCLED peaked at λ=3.96 μm. These are among the longest operating wavelengths for III–V RCE photodetectors and RCLEDs reported in the literature.