光束的时空调制对自相关信号影响分析  

Effect of Temporal and Spatial Modulation on Noncollinear Autocorrelation

作　　者：孙志红[1] 夏彦文[1] 刘华[1] 傅学军[1] 

机构地区：[1]中国工程物理研究院激光聚变研究中心,四川绵阳621900

出　　处：《光学学报》2010年第10期3005-3009,共5页Acta Optica Sinica

基　　金：中国工程物理研究院激光聚变研究中心和等离子体物理国家级重点实验室创新基金资助课题

摘　　要：通过采用分步傅里叶变换方法求解非共轴相关耦合波方程,分析了单发次自相关方法测试脉冲宽度时光束空间和频率调制对自相关信号的影响。分别讨论了两束基频光都存在空间调制和一束基频光在传输光路中强度分布受到调制等情况下的谐波信号变化。模拟结果表明谐波信号的调制随入射基频光调制度增大而增加,随基频光强调制频率增大而减少。相关信号外包络线与光束未调制情况下得到的结果一致,脉冲啁啾只是导致自相关信号效率降低。提出了基于自相关函数外包络线求解被测试信号脉冲宽度的方法,为正确测试脉冲宽度提供了理论依据。The slip step Fourier transform method is adopted to study the coupled-wave equation of noncollinear autocorrelator.The influence of spatial intensity distribution and pulse chirp of the fundamental beams on measurement of pulse duration of second-order autocorrelation signal are simulated.Two fundamental beams and only one fundamental beam modulated by spatial intensity distribution are respectively discussed.It is shown that the irregular spatial intensity distribution modulation of the second harmonic beams increases with the fundamental beam modulation and decreases with modulated intensity increase of the fundamental beam.The outside envelope of the autocorrelation with irregular spatial intensity distribution is the same as that of the autocorrelation without modulation.The pulse chirp only leads to efficiency decrease of autocorrelation.The method of pulse duration derived from outside envelope of autocorrelation is presented.The analyzing results are of reference value for the exact measurement of pulse duration.

关 键 词：非线性光学 脉冲宽度 分步傅里叶变换 单发次自相关 调制度 

分 类 号：TN241[电子电信—物理电子学]