基于时分复用的多路任意时间整形前端系统  

Multiplexed Arbitrary Time Shaping Front⁃End System Based on Time Division Multiplexing

作　　者：张雨佳 汪小超[1,2] 肖助力 张生佳[1] 范薇[1,2] Zhang Yujia;Wang Xiaochao;Xiao Zhuli;Zhang Shengjia;Fan Wei(National Laboratory on High Power Laser and Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海光学精密机械研究所高功率激光物理联合实验室,上海201800 [2]中国科学院大学材料与光电研究中心,北京100049

出　　处：《中国激光》2024年第23期23-33,共11页Chinese Journal of Lasers

摘　　要：精密的脉冲时间整形是高功率激光装置运行控制以及进行精密物理实验的关键技术之一。在高功率激光装置前端系统中,利用时分复用技术产生多路信号时各脉冲之间会出现串扰,为了解决这一问题,进一步提升激光脉冲的时间整形特性,本课题组提出了一种基于时分复用的多路输出高功率激光装置前端系统。该系统利用射频开关对任意信号发生器(AWG)的输出进行时间“切片”,然后将其输出作用于独立的电放大和电光调制,实现了基于单台AWG的多束光脉冲的任意整形输出。研究结果表明,该系统可以在保持整形精度的情况下有效提升输出脉冲的信噪比,避免了信号间的相互影响。基于AWG的单通道获得了4路任意时间整形的激光脉冲,实现了上升沿为55 ps、脉宽为67 ps~25 ns、脉冲对比度大于500:1的输出,而且每级电光调制器信噪比的提升不低于2 dB。Objective Precise pulse-time shaping is a key technology for operation control and precise physics experiments in high-power laser facilities.Inertial confinement fusion(ICF)laser drivers require that the front-end system generates arbitrary shaping optical pulses to satisfy the time waveform requirements of target physics experiments.To reduce the number of arbitrary waveform generators(AWGs)in a system,multiple shaping pulses are typically generated in the form of pulse trains.However,in the process of time shaping,the earlier pulses affect later pulses.This effect is amplified during the subsequent transmission of the pulse,and this reduces pulse quality.In the pulse generation systems of ICF laser drivers,this effect is detrimental to the precise pulse time shaping of the injected laser,reducing the energy utilization rate of the laser pulse.This significantly affects aspects such as the energy transmission and focusing of the laser,target ablation,plasma formation,and fusion reaction efficiency.The front-end systems of high-power laser facilities generate multiple pulses by utilizing time division multiplexing technology.Therefore,the objective of this study is to solve the crosstalk problem between multiple pulses and further improve the time shaping characteristics of laser pulses.Methods Figure 2 shows the front-end system structure of a multi-output high-power laser facilities based on time division multiplexing.First,the continuous-wave laser required by the system was generated and then modulated using an acousto-optic modulator(AOM)into a microsecond pulsed laser.The output is amplified using a fiber amplifier to increase the energy of the pulsed laser.Subsequently,a four-way fiber beam splitter was used to divide the pulsed laser into four outputs,which then entered their respective electro-optical modulators.Simultaneously,a sequence pulse containing four sub-pulses was generated by a high-precision AWG;this pulse can be independently and arbitrarily shaped.Subsequently,after being selected as a sin

关 键 词：前端系统 时分复用 射频开关 信噪比 对比度 

分 类 号：TN248.1[电子电信—物理电子学]