单发次皮秒脉冲对比度的三阶自相关法测试技术  

Contrast ratio measurement of single shot picosecond pulse using third-order noncollinear autocorrelation technique

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：《强激光与粒子束》2010年第8期1852-1856,共5页High Power Laser and Particle Beams

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项目

摘　　要：为了测试单发次皮秒脉冲对比度,设计并研制了非共轴三阶自相关仪。三阶自相关仪参数优化设计中,在确保获得正确的相关耦合信号的前提下,充分利用KDP晶体的极化张量,寻找有效非线性系数相对较高的相位匹配点,在满足非共线相位匹配条件的同时兼顾群速匹配,为增大时间测试范围,选取较大的入射光夹角。采用分区测试和图形重构技术,增大对比度测试的动态范围,结果显示采用两个科学级CCD测试的脉冲对比度在105左右。A noncollinear third-order autocorrelator was designed and manufactured for contrast ratio measurement of single shot picosecond pulses.Under the premise of obtaining correct cross-correlation signals during the parameters optimization,it was still important to consider the conversion efficiency of the third harmonic wave.The noncollinear phase matching value with the maximum efficient nonlinear coefficient was taken into account according to the polarization tensor of a nonlinear crystal KDP.The noncollinear phase matching and group-velocity mismatch were synchronously satisfied,and large noncollinear angles of the incident pulses were selected for the increase of the test range of time.The prepulse and main peak were separately measured,and two-image reconstructive technology was adopted in our measurement to increase the dynamic range.It is shown that the contrast ratio of the laser system is about 105 using two scientific-grade CCDs.

关 键 词：皮秒脉冲 单发次 非共轴三阶自相关 对比度 非线性晶体 

分 类 号：TN247[电子电信—物理电子学]