强激光与粒子束, 2009, 21 (1): 34, 网络出版: 2009-11-24
光学参量啁啾脉冲放大中时间抖动对飞秒脉冲对比度的影响
Influences of synchronization time jitter in OPCPA system oncontrast ratio of femto-second pulse
摘要
基于宽带脉冲的计算模型,采用4阶龙格-库塔法研究了光学参量放大所满足的三光波耦合方程。数值结果表明:时间不同步导致大量本底能量不能被压缩,使本底形成,导致飞秒脉冲展宽,如抖动从0变化到150 ps,则其预脉冲宽度由0.2 ps展宽到0.7 ps,降低了输出飞秒激光对比度,并导致输出能量稳定性降低。采用长而平滑泵浦光脉冲、选择适当长度的非线性晶体、并使系统工作于增益饱和区,能实现高对比度和高稳定的飞秒激光输出。
Abstract
Based on the propagation model for the wideband ultra-short pulse,the coupled equations which determine the interaction process among pump,idle and signal pulses in the LBO crystal are studied by the fourth-order Runge-Kutta methods. The simulation results are as follows: the synchronization time jitter induces the pedestal generation,which possesses plentiful energy and can not be removed in the compression stage,therefore,the pulse duration stretches and the contrast ratio of the femto-second pulses decreases seriously,for example,the prepulse stretches from 0.2 ps to 0.7 ps when the synchronization time jitter changed from 0 to 150 ps;Using the longer duration and smoother shape pump pulse can restrain the time jitter effectively,and choosing suitable length of the nonlinear crystal,the femto-second pulse with high contrast and high gain stability can be obtained when the OPCPA system is operating in the saturation region.
马再如, 冯国英, 陈建国, 周寿桓. 光学参量啁啾脉冲放大中时间抖动对飞秒脉冲对比度的影响[J]. 强激光与粒子束, 2009, 21(1): 34. Ma Zairu, Feng Guoying, Chen Jianguo, Zhou Shouhuan. Influences of synchronization time jitter in OPCPA system oncontrast ratio of femto-second pulse[J]. High Power Laser and Particle Beams, 2009, 21(1): 34.