基于双通预脉冲清洁及腔内频谱滤波的高对比度飞秒激光再生放大器  

High Contrast Femtosecond Laser Regenerative Amplifier Based on Dual-channel Pre-pulse Cleaning and Intracavity Spectral Filtering

作　　者：李鹏飞 赵遵成[1,2] 鲁巍 洪德昇[4] 陈培荣 张传标 田晓光 刘畅 陈聪 LI Pengfei;ZHAO Zuncheng;LU Wei;HONG Desheng;CHEN Peirong;ZHANG Chuanbiao;TIAN Xiaoguang;LIU Chang;CHEN Cong(School of Physics and Electronics,Henan University,Kaifeng,Henan 475004,China;Henan Engineering Research Center of Metal Matrix in situ Composites Based on Aluminum,Magnesium or Copper,Henan University,Kaifeng,Henan 475004,China;Tsinghua University,Beijing 100000,China;Beijing Academy of Quantum Information Sciences,Beijing 100000,China;Newlight Source Qifeng Technology,Henan 475000,China)

机构地区：[1]河南大学物理与电子学院,河南开封475004 [2]河南大学河南省铝镁铜基原位复合金属材料工程实验室,河南开封475004 [3]清华大学工程物理系,北京100000 [4]北京量子信息科学研究院,北京100000 [5]河南省启封新源光电科技有限公司,河南开封475000

出　　处：《光子学报》2022年第11期132-141,共10页Acta Photonica Sinica

基　　金：河南省重大科技专项科研基金(No.181100211300)。

摘　　要：为了提高再生放大器输出激光脉冲的对比度,需要同时提高激光脉冲纳秒尺度的对比度和皮秒尺度的对比度。利用普克尔盒对主脉冲和预脉冲时间滤波的方法,设计了普克尔盒的双通预脉冲清洁装置,通过该装置使再生放大器输出激光纳秒尺度的预脉冲对比度提高了5个数量级;利用频谱整形方法,通过在放大器腔内适当位置插入频谱整形滤波片使得主脉冲前400 ps处的放大自发辐射对比度提高了1个数量级。最终,在双通预脉冲清洁与腔内频谱滤波共同作用下,再生放大器输出激光纳秒尺度的预脉冲对比度从4.3×10^(−4)提高到了6.6×10^(−10),放大自发辐射对比度(主脉冲前400 ps)从5.0×10^(−8)提高到了5.0×10^(−9)。In experiments of pulsed laser-matter interaction,pre-pulse with higher peak power interacting with matter produces a plasma that corrupts the experimental results.To avoid this problem,it is necessary to reduce the peak power of the pre-pulses.Therefore,it is necessary to find a way to improve the temporal contrast of the pulsed laser,which is also the main purpose of this paper.When using chirped pulse amplification technology to design femtosecond Ti:sapphire regenerative amplifier with high peak power,on the one hand,the amplified spontaneous emission in the amplified laser will be amplified before the seed light,so the temporal contrast of the amplified spontaneous emission of the amplified laser will be low;on the other hand,due to the low extinction ratio of the polarization selective device in the amplifier,the pre-pulse temporal contrast of the amplified light will be low,both of which will lead to low temporal contrast of the amplified light.In order to improve the temporal contrast of laser pulse output by regenerative amplifier,it is necessary to improve the temporal contrast of nanosecond and temporal contrast of picosecond laser pulse simultaneously.On the one hand,this paper studies the influence of a compact dual-channel pulse cleaner for the Pockels Cells on nanosecond pre-pulse temporal contrast,through this device,two laser pulse cleaning can be completed on a set of the Pockels Cells which makes the pre-pulse temporal contrast of regenerative amplifier by 5 orders of magnitude.On the other hand,the influence of the position where the regenerative amplifier is inserted into the spectral shaping filter on laser pulse amplified spontaneous emission contrast is studied.By inserting the spectral shaping filter in an appropriate position in the ring cavity and adjusting the angle of the spectral shaping filter,the position with the lowest actual transmittance of the spectral shaping filter is just the position with the strongest amplified spontaneous emission spectral intensity in the ring cavity.It

关 键 词：飞秒激光 再生放大器 双通预脉冲清洁 腔内频谱滤波 频谱整形滤波片 对比度 

分 类 号：TN248[电子电信—物理电子学]