双光子中心对称光折变宽光束调制不稳定性  

Modulation instability of broad optical beams in biased two-photon centrosymmetric photorefractive crystals

作　　者：吉选芒[1] 姜其畅[1] 刘劲松[2] 

机构地区：[1]运城学院物理与电子工程系,运城044000 [2]华中科技大学光电子科学与工程学院,武汉430074

出　　处：《激光技术》2011年第6期813-816,共4页Laser Technology

基　　金：山西省高等学校科技开发基金资助项目(200611042)

摘　　要：为了得到稳态条件下1维宽光束在有偏压双光子中心对称光折变晶体中的调制不稳定性的结果,通过空间电荷场的局域性处理和数值模拟的方法,获得了1维调制不稳定性的增长率。结果表明,在入射光束强度一定的情况下,调制不稳定性增长率最大值随外加电场以及空间频率域的增加而增大;在外加电场给定时,调制不稳定性增长率的最大值随入射光强的增大先达到一峰值后又减小。宽光束的调制不稳定性取决于外加电场及入射光束强度与暗辐射的比值。In order to obtain the modulation instability of 1-D broad optical beams in biased two-photon centrosymmetric photorefractive crystals under steady-state conditions, the growth rate of 1-D modulation instability was obtained by means of numerical simulation method after treating the space-charge field locally. The numerical results show that the maximum modulation instability growth rates increases linearly with the external electric field and spatial-frequency when the incident optical intensity is constant. When the external electric field is fixed, the maximum modulation instability growth rates increases to a maximum then decreases as the incident optical intensity increases. The modulation instability of 1-D broad optical beams depends on the external bias field and the ratio of optical beam＇ s intensity to that of the dark irradiance.

关 键 词：非线性光学 中心对称光折变晶体 双光子光折变效应 调制不稳定性 

分 类 号：O437[机械工程—光学工程]