用于冷原子制备的激光扩束准直器的研制

针对现有的冷原子实验用的多数保偏光纤输入型扩束准直器不能对输入激光束的偏振进行精确调节的缺陷,提出了一种全长度为135mm,输出圆形光斑有效直径为20mm的紧凑型偏振可调激光扩束准直器.该扩束准直器中的偏振棱镜和波片偏振轴均可独立调节,能对单模保偏光纤输入光束的偏振态进行精确调节和保持.所研制的激光扩束准直器在三维磁光阱冷原子实验中制备出了满足冷原子干涉实验要求的冷原子团,冷原子团原子数为5×108,温度约为10μK,并获得了最大上抛高度为1.156m的原子喷泉飞行时间信号.     

共口径宽光谱复眼光学系统设计

为了扩大复眼光学系统的接收光谱,研究了一种可见光、长波红外复眼光学系统.推导了双波段共焦面方程,建立了子眼系统与接收系统的匹配要求.子眼光学系统的工作波段为0.38~0.78μm和8~12μm,焦距为5mm,相对孔径为1∶3,视场为10°.两个波段的子眼系统成像位置均为2.92mm,相邻的两个中心光轴夹角为4.016°,共650个子眼,合并后的视场为90°.接收系统的焦距为4mm,视场为80°,相对孔径为1∶3.子眼系统和接收系统的图像质量良好,在-40~60℃的温度范围内无热差影响.     

Self-trapped spatially localized states in combined linear-nonlinear periodic potentials

We analyze the existence and stability of two kinds of self-trapped spatially localized gap modes,gap solitons and truncated nonlinear Bloch waves,in one-and two-dimensional optical or matter-wave media with self-focusing nonlinearity,supported by a combination of linear and nonlinear periodic lattice potentials.The former is found to be stable once placed inside a single well of the nonlinear lattice,it is unstable otherwise.Contrary to the case with constant self-focusing nonlinearity,where the latter solution is always unstable,here,we demonstrate that it nevertheless can be stabilized by the nonlinear lattice since the model under consideration combines the unique properties of both the linear and nonlinear lattices.The practical possibilities for experimental realization of the predicted solutions are also discussed.     

A facile route to perylenequinone

Two-stage Ullmann and phenol coupling were effected in a singleoperation on methyl 5-bromo-1,2-dihydroxy-6,8-dimethoxynaphthalene-3-acetate to give dimethyl 5,8-dihydroxy-1,3,10,12-tetramethoxy-4,9-perylenequinone-6,7-diacetatewith ferric chloride as oxidant.     

Nuclear matter properties in the relativistic Λ-approximations

In the framework of relativistic nuclear field theory the nuclear matter parameters were calculated in the so-called Λ⁰⁰- and approximation of the Green function theory. For the nucleon-meson coupling constants we used parameter sets given by the Bonn and Groningen group. The results show no significant differences with those obtained from the relativistic Brueckner theory.     

Photoluminescence enhancement of InP treated with activated hydrogen

A large enhancement of the photoluminescence intensity emitted by a (100)-oriented InP surface after exposure to activated hydrogen, indicating a sharp reduction of the surface recombination rate is reported in this work. It is shown, using capacitance-voltage measurements performed on metal-insulator-semiconductor structures, that the hydrogen treatment results also in a strong pinning of the interface Fermi level. These phenomena are interpreted on the following basis: (i) neutralization by hydrogen species of active recombination centers which are deemed to be phosphorus dangling bonds; (ii) creation of pinning surface states due to the formation of volatile phosphorus hydride compounds freeing excess indium atoms.     

基于CPLD的空间面阵CCD相机驱动时序发生器的设计与硬件实现

在分析e2v公司的CCD47-20 Backthinned NIMO型CCD器件驱动时序关系的基础上, 设计了可调帧频和曝光时间的空间面阵CCD相机驱动时序发生器及其硬件电路.选用可编程逻辑器件作为硬件设计载体,使用VHDL语言对驱动时序发生器进行了硬件描述.针对ALTERA公司的EPM9400LC84-15对设计进行了RTL级仿真及配置,完成了时序发生器的硬件电路.硬件实验结果表明,所研制的驱动时序发生器不仅可以满足空间CCD相机的驱动要求,而且还可以调节帧频和曝光时间.     

一种新型Sagnac式光纤电流传感器

为了消除震动对Sagnac式电流传感器测量结果的影响,提出一种光路改进方法来消除传感器对震动的敏感性,其基本原理是抵消Sagnac效应而不影响法拉第磁光效应。利用琼斯矩阵对改进后的光路结构进行了偏振态分析,理论分析和实验结果吻合,表明改进后的传感器其输出与震动无关。耦合半波片后Sagnac式光纤电流传感器的震动敏感性被消除了,为Sagnac式光纤电流传感器的工程化实现提供了一种可行的方法。     

基于光场摄像技术的对焦测距方法的研究

提出一种新的基于光场摄像技术的单站非合作目标测距方法,介绍了该方法的原理及系统组成.对基于光场摄像测距方法的图像处理技术进行了数学分析研究,给出了图像处理公式.对像面判读函数进行了研究,结合条纹鉴别率板通过实验方法统计分析了像面判读误差.理论分析了该测距技术测距准确度和测距范围.