1982年美国光学学会年会

1982年美国光学学会年会于10月18日至22日在美国阿里桑那州的图森(Tacson)举行.约有2000人出席会议,报告文章约600篇(包括邀请报告、展讲报告和过期报告在内).诺贝尔物理学奖金获得者N.Bloembergen和A.L.Schawlow出席了会议,并主持了“激光和非线性光学发展史”的专题演讲.这次会议的指导委员会由贝尔实验室、航空与宇航协会、罗彻斯特大学、阿里桑那大学、林肯实验室和Times光纤通讯公司的代表组成,由阿里桑那大学光学科学中心的H.A.Macleod教授担任节目委员会主席.参加这次会议的代表除美国外,还有世界各国的代表.约有30名中国代表(包括在美的访问学者)出席会议和宣读论文.     

采用PZT动态调制的光纤光栅应变力测量技术

提出了一种新型PZT的动态调制光纤光栅应变力测量技术。把光谱仪对峰值波长移动的测量改变为示波器对峰值光功率时间间隔的测量 ,并对这种技术进行了理论分析和实验研究。用交变电压调制固定在光纤光栅上的PZT ,同时对施加在光栅上的应力进行测量。实践证明 ,测光脉冲时间间隔法与光谱峰值移动法的测量结果相同 ,而且两者与理论计算结果相符     

基于耦合双振子模型的手性分子的超极化率

本文从手性分子的耦合双振子经典模型出发,推导出手性分子的超极化率.在特定情况下,给出了三阶非线性极化率的表达式.基于该模型讨论了手性介质分子各向同性分布的宏观非线性极化率.     

NONLINEAR REFRACTION IN MULTILEVEL MOLECULAR SYSTEMS

The intensity-dependent nonlinear refraction phenomena in a non-resonant multilevel molecular system is studied using rate equations in steady state, including saturable refraction, reverse saturable refraction, and the turnover between these two effects. The relationship between the refraction saturation and the optical Kerr effect is also discussed.     

RELATIONSHIP BETWEEN INTENSITY OF SURFACE SECOND HARMONIC GENERATION AND MOLECULAR STRUCTURE IN HELIX MOLECULAR FILMS

The relationship between intensity of surface Second Harmonic Generation (SHG) and the pitch, radius and azimuthal angle of molecules on the surface of helix molecular films is analyzed. The values of pitch and radius corresponding to the maximal intensity of SHG have been shown to exist. The theoretical results are compared with the experimental ones reported by M?hlman et al., and the limitation of their conclusion is also pointed out.     

非导电型各向同性手性介质中非线性旋光的宏观理论

采用经典电磁场理论描述非导电型各向同性手性介质,研究了圆偏振抽运光作用下线偏振信号光的非线性旋光现象．给出了非线性旋光角的解析表达式．用该公式计算的结果与实验结果一致. 关键词：     

手持式眼底相机光学系统设计

提出一种新型眼底成像系统,结构更加简单、紧凑。系统的成像和调焦投影光路共用调焦镜,调焦投影光路完全嵌入到照明光路。调焦投影光路不再专设照明组件,避免了投影目标和调焦镜之间的机械联动结构。并且充分利用了网膜物镜系统的空间。利用LED光源窄带宽的优势,瞄准和拍照过程共用一个电荷耦合器件相机。采用新的光学结构,设计了一款视场30°、工作距离30mm的眼底相机光学系统,眼光焦度补偿范围-10m-1～+5m-1,物方各视场分辨率为45line/mm,畸变小于5%。     

Numerical analysis of In0.53Ga0.47As/InP single photon avalanche diodes

A rigorous theoretical model for In 0.53 Ga 0.47 As/InP single photon avalanche diode is utilized to investigate the dependences of single photon quantum efficiency and dark count probability on structure and operation condition.In the model,low field impact ionizations in charge and absorption layers are allowed,while avalanche breakdown can occur only in the multiplication layer.The origin of dark counts is discussed and the results indicate that the dominant mechanism that gives rise to dark counts depends on both device structure and operating condition.When the multiplication layer is thicker than a critical thickness or the temperature is higher than a critical value,generation-recombination in the absorption layer is the dominative mechanism;otherwise band-to-band tunneling in the multiplication layer dominates the dark counts.The thicknesses of charge and multiplication layers greatly affect the dark count and the peak single photon quantum efficiency and increasing the multiplication layer width may reduce the dark count probability and increase the peak single photon quantum efficiency.However,when the multiplication layer width exceeds 1 μm,the peak single photon quantum efficiency increases slowly and it is finally saturated at the quantum efficiency of the single photon avalanche diodes.     

手性分子介质非线性光学研究新进展

文章介绍了近年来手性分子介质及材料的非线性光学性质的研究状况，综述了手性分子非线性微观模型的使用情况，给出了一些典型的二阶、三阶非线性光学实验结果，用这些微观模型可以正确地分析这些结果．同时指出了未来研究的趋势，及研究成果可能应用的领域．     

A Novel All-Optical Switch in a Double-Loop Sagnac Ring Coupled with a Nonlinear Ring Resonator

We propose a novel configuration of all-optical switch based on a double-loop Sagnac ring coupled with a nonlinear ring resonator. In the case of self-phase modulation, the reducing switching threshold power clown to mW is predicted, which is the improvement of earlier works on all-optical switches. The switch optimization is analysed.A way to increase the response speed of all-optical switches is suggested.