非线性迭层光栅的光学限制特性  

CHARACTERISTIC OF OPTICAL LIMITING INNONLINEAR STRATIIED GRATING

作　　者：刘大力[1] 李公羽 何晓东 孙雅东[1] 赵昱 祁雷[1] 林久令[2] 范俊清 徐迈[2] 范希武[2] 

机构地区：[1]长春邮电学院,吉林长春130012 [2]中国科学院激发态物理开放研究实验室,吉林长春130021

出　　处：《发光学报》1999年第4期368-371,共4页Chinese Journal of Luminescence

基　　金：国家自然科学基金

摘　　要：首次报导了在具有非线性响应的ＺｎＳ／ＺｎＳｅ迭层光栅中实现的光学限制效应，其光学限制阈值大约为１４０ｍＷ（１．４２×１０５Ｗ／ｃｍ２），限幅阈值２４ｍＷ．理论分析表明，这种迭晨光栅的光学限制机理是来自双光子吸收产生的自由载流子引起的自散焦效应对材料折射率的贡献，产生了非线性折射率的结果．我们发现这种由半导体多层结构制成的光功率限制器不但具有较低的阈值和较宽的频谱响应，而且具有其阈值强度依赖于器件的各种参数的特点．因此，它比单层结构的功率限制器的适应性更强．For solving 'bottlenects effects' in a computer and improving its calculation rates,optical interconnections within a computer are now well investigated in the world. Andas one of the basis of optical digital computer, all-optical interconnections are also extensively studied in recent years. All-optical interconnections within digital optical computing systems requir that light beam carrying information be deflected to another position reqired from one position to realize real-time, optical addressing. In this paper weproposed a new method for solving such a problem, namely stratified grating composedof nonlinear media characterized by light intensity-dependent refractive indices was usedas a basic optical interconnection device, so Bragg reflecting condition of incident signallight in the grating is changed by means of refractive index change of the nonlinearmedia caused by the change of external controlling light intensity, then the signal beamis deflected to a position reqired. The optical limiting effect realized in ZnS/ZnSe stratified grating is reported in this paper for the first time, and the nonlinear threshold isabout 140mW, the limiting threshold is 24mW. It shows that the dominant mechanismsof the optical limiting in the experiment is the large photogenerated free-carrierdefocusing contribution to the linear refractive index of the material from the two-photon absorption (2PA ). The optical limiter fabricated by multiple layers structure ofsemiconductor materials has not only lower threshold and wider frequency response, butalso the characteristics of which the threshold of the limiter is dependent on all kinds ofparameters of the device. So its adaptability is superior to single layer structurelimiter's.

关 键 词：迭层光栅 光学限制 自散焦 非线性 

分 类 号：O437[机械工程—光学工程] TN256[理学—光学]