基于半导体光放大器的纳秒脉冲串激光种子源系统  

Nanosecond Pulse⁃Train Laser Seed Source System Based on Semiconductor Optical Amplifier

作　　者：黄磊 邱基斯 齐耀东 袁峰 刘昊 Huang Lei;Qiu Jisi;Qi Yaodong;Yuan Feng;Liu Hao(Optical Engineering Research Department,Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100094,China;School of Optoelectronics,University of Chinese Academy of Sciences,Beijing 100094,China)

机构地区：[1]中国科学院空天信息创新研究院光学工程研究部,北京100094 [2]中国科学院大学光电学院,北京100094

出　　处：《中国激光》2024年第14期72-79,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(22227901)。

摘　　要：设计了一种基于半导体光放大器的纳秒脉冲串激光种子源系统。在该系统中,半导体光放大器具有40 dB以上的高消光比,可实现高信噪比的脉冲串激光输出。利用半导体光放大器腔外调制窄线宽连续激光光源,研究了不同重复频率下纳秒脉冲串激光的输出特性,通过调控触发信号实现了子脉冲重复频率为10~100 kHz、子脉冲脉宽为8.6~88.2 ns、单脉冲能量为0.892~6.124μJ的高光束质量1064 nm脉冲串激光输出,最大平均功率为86.4 mW,输出不稳定度为1.66%,横向光束质量因子(M_(x)^(2))和纵向光束质量因子(M_(y)^(2))分别为1.12和1.16。该系统可作为高平均功率纳秒脉冲串激光器的种子源系统。Objective A pulse-train laser refers to a laser that has a“continuous”pulse output over a period of time with multiple sub-pulses included in a pulse envelope.The characteristics of intermittent operation can,to some extent,alleviate the thermal effect of continuous laser output.However,in the development process of pulsed lasers,the background noise between pulses and the gain saturation effect of the amplification stage restrict the further development of pulsed lasers toward high peak power.Currently,pulse trains are mostly generated using electro-optical modulators (EOMs) and free-space acousto-optic modulators (AOMs) to chop the continuous laser output.This out-of-cavity modulation method can directly control the amplitude and interval of sub-pulses in the pulse-train envelope.However,background noise between sub-pulses remains a problem.Simultaneously,the obtained single-pulse energy requires a system gain of 10^(7)~10^(9) levels to generate high-energy output at the nanojunction level.Therefore,investigating high extinction ratio pulse-train-laser generation technology with single-pulse energy above theμJ level,along with flexible and adjustable time-domain parameters,is of great significance for the development of pulse-train lasers in terms of high repetition rate and high peak power.Methods In this study,a semiconductor optical amplifier (SOA) is used to modulate a 1064-nm continuous laser source outside the cavity to produce a pulse-train laser.We use the SOA as a modulation device to chop 1064-nm continuous light from distributed feedback (DFB) lasers under amplification and absorption with and without trigger signal excitation to generate optical pulses.Through measurements of the output spectrum of the SOA,the signal-to-noise ratio (SNR),extinction ratio,and other SOA performances are analyzed.The repetition frequency,pulse width,and single-pulse energy of the output pulse-train laser are controlled by designing the time-domain parameters of the trigger signal and the power of the input light.B

关 键 词：激光器 半导体光放大器 脉冲串激光 激光器种子系统 

分 类 号：TN248.4[电子电信—物理电子学]