Dependence of femtosecond time-resolved magneto-optical Kerr rotation on the direction of polarization of the probe beam

作     者：FENG XiaoBo LI Yan QIN Yi XIAO YunFeng YANG Hong GONG QiHuang 

作者机构：State Key Laboratory for Mesoscopic Physics and Department of Physics Peking University Beijing 100871 China 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2011年第54卷第8期

页      面：1411-1415页

核心收录：

学科分类：081702[工学-化学工艺] 070207[理学-光学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 10821062 and 11074013) 

主　　题：time-resolved Kerr rotation spin dynamics direction of polarization 

摘      要：We demonstrate that the femtosecond time-resolved magneto-optical Kerr rotation oscillates with the direction of polarization of the probe beam when a sample of Al0.25Ga0.75As/GaAs multi-quantum wells is excited by a circularly polarized pump and detected by a linearly polarized probe at wavelengths from 800 to 830 nm. Analytical expressions are derived to explain the mechanism, which is in good agreement with the numerical computation and the experimental data. The results suggest that the Kerr signal can be enhanced by choosing an optimal direction of polarization, which is of benefit to the measurement of the weak Kerr rotation.