飞秒脉冲激光啁啾对4,4’-二(二正丁胺基)二苯乙烯的光限幅及动态双光子吸收的影响(英文)  

Influence of Femtosecond Laser Chirp on Optical Limiting and Dynamical Two-photon Absorption of 4,4' -bis( di-n-butylamino) stilbene Compounds

作　　者：张玉瑾[1] 张秋月[1] 宋玉志[1] 王传奎[1] 

机构地区：[1]山东师范大学物理与电子科学学院

出　　处：《计算物理》2015年第1期65-74,共10页Chinese Journal of Computational Physics

基　　金：Supported by 973 Program(2011CB808100)

摘　　要：通过采用预估矫正的时域有限差分方法(FDTD)数值求解Maxwell-Bloch方程,研究飞秒啁啾脉冲激光在4,4’-二(二正丁胺基)二苯乙烯(BDBAS)分子介质中的光限幅行为(OL)和动态双光子吸收(TPA)截面.计算表明啁啾率的符号和大小都对频谱演化和光限幅行为产生影响.啁啾率的符号决定频移的方向:正啁啾对应频谱蓝移,负啁啾对应频谱红移.随着啁啾率绝对值的增大,频移更加明显,光限幅窗口变窄,同时出射光强饱和值变大.有趣的是,当负啁啾降低到一定值(-0.025/fs2)时,出现自感应透明(SIT)现象.另外,动态双光子吸收截面在考虑啁啾效应的情况下减小.本研究提供了一种控制非线性光学吸收的方法.Optical limiting （OL） and dynamical two-photon absorption （TPA） of 4,4’-bis（di-n-butylamino）stilbene （BDBAS） molecules in chirped femtosecond laser pulses are studied by solving Maxwell-Bloch equations with an iterative predictor-corrector finite-difference time-domain （ FDTD） method. It shows that both sign and magnitude of chirp rate influence greatly spectrum evolution and OL behavior. Spectra exhibit obvious carrier frequency shifts depending on sign of chirp rate, blue shift for positive chirp rate and red shift for negative chirp rate. As absolute chirp rate increases, shift becomes more obvious, OL window gets narrower and saturation of output intensity becomes greater. Interestingly, self-induced transparency （ SIT） appears as a negative chirp rate reduces to a certain value （ -0-025 fs-2 ） . Dynamical TPA cross section is reduced as chirp effect is considered. It provides a method for controlling nonlinear optical absorptions.

关 键 词：双光子吸收 光限幅 啁啾脉冲 有机分子 

分 类 号：O437[机械工程—光学工程] O561.1[理学—光学]