Optical power limiting of ultrashort hyper-Gaussian pulses in cascade three-level system  

作　　者：Ji-Cai Liu Fen-Fen Guo Ya-Nan Zhao Xing-Zhe Li 刘纪彩;郭芬芬;赵亚男;李兴哲(Department of Mathematics and Physics,North China Electric Power University)

机构地区：Department of Mathematics and Physics,North China Electric Power University,Beijing 102206,China

出　　处：《Chinese Physics B》2018年第10期357-361,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.11574082);the Fundamental Research Funds for the Central Universities,China(Grant No.2018MS050)

摘　　要：Propagation of strong femtosecond hyper-Gaussian pulses in a cascade three-level molecular system is studied by solving numerically the Maxwell–Bloch equations by the iterative predictor-corrector finite-difference time-domain method.Optical power limiting behavior induced by strong nonlinear two-photon absorption is observed for different orders of the femtosecond hyper-Gaussian pulses. Pulses of a higher order temporal profile are found to have a wider power range of optical limiting but a larger output saturation intensity. Both the output saturation value and the damage threshold of optical power limiting decrease with pulse duration increasing. The decrease of the pulse area along the pulse propagation is much slower than that obtained from the two-photon area theorem due to invalidity of the slowly varying amplitude approximation and the monochromatic field hypothesis.Propagation of strong femtosecond hyper-Gaussian pulses in a cascade three-level molecular system is studied by solving numerically the Maxwell–Bloch equations by the iterative predictor-corrector finite-difference time-domain method.Optical power limiting behavior induced by strong nonlinear two-photon absorption is observed for different orders of the femtosecond hyper-Gaussian pulses. Pulses of a higher order temporal profile are found to have a wider power range of optical limiting but a larger output saturation intensity. Both the output saturation value and the damage threshold of optical power limiting decrease with pulse duration increasing. The decrease of the pulse area along the pulse propagation is much slower than that obtained from the two-photon area theorem due to invalidity of the slowly varying amplitude approximation and the monochromatic field hypothesis.

关 键 词：optical power limiting two-photon absorption ultrashort hyper-Gaussian pulse cascade three-level system 

分 类 号：O437[机械工程—光学工程]