基于台阶声光调Q外腔泵浦MgO:PPLN光参量振荡器的3.4μm中红外脉冲串激光器  

3.4μm mid-infrared pulse train laser based on stepped acousto-optic Q-switched external cavity pumped MgO:PPLN optical parametric oscillator

作　　者：姚晓岱 吴爽 赵锐 吴淼鑫 刘航[1] 金光勇[1] 于永吉[1,2] Yao Xiao-Dai;Wu Shuang;Zhao Rui;Wu Miao-Xin;Liu Hang;Jin Guang-Yong;Yu Yong-Ji(Jilin Key Laboratory of Solid Laser Technology and Application,School of Physics,Changchun University of Science and Technology,Changchun 130022,China;Chongqing Research Institute,Changchun University of Science and Technology,Chongqing 401135,China)

机构地区：[1]长春理工大学物理学院,吉林省固体激光技术与应用重点实验室,长春130022 [2]长春理工大学重庆研究院,重庆401135

出　　处：《物理学报》2024年第4期192-199,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:U20A20214,62275031,11974060);重庆市自然科学基金(批准号:CSTB2022NSCQ-MSX1027);吉林省自然科学基金(批准号:20210101154JC)资助的课题.

摘　　要：本文报道了一种台阶声光调Q外腔泵浦MgO:PPLN光参量振荡器的3.4μm中红外脉冲串激光器.建立了基频台阶声光调Q理论模型,模拟了不同台阶调Q间隔时光子数密度随时间变化趋势,获得了台阶信号最优触发时间,确定了台阶声光调Q获得脉冲串激光输出的可能性.根据理论模拟设计台阶信号触发时间,并应用于台阶声光调Q外腔泵浦MgO:PPLN光参量振荡器的中红外脉冲串激光器实验中,在每个重复周期内声光Q开关分三次开启,获得了单脉冲包络含三个子脉冲的3.4μm中红外脉冲串激光输出.脉冲包络内子脉冲间隔为5μs,最窄脉宽为12.8 ns,脉冲包络重频为20 kHz,理论和是实验中均发现脉冲包络内子脉冲宽度逐渐增大.在最大平均输出功率为1.08 W时,1064 nm基频光与3.4μm参量光的光-光转换效率为10.05%,光束质量因子M 2为2.01.3.4μm mid-infrared pulse train laser generates the characteristic spectral lines of absorption peaks of CH4,NO2 and other molecules.Its pulse train working mode can increase the signal-to-noise ratio of laser detection echo signal.It has broad application prospects in radar detection,environmental monitoring,spectral analysis and other fields,which has aroused great interest of scientists.Compared with the traditional intra-cavity control method,the step Q-switching method has the advantages of simple structure,high energy utilization rate and accurate control.Therefore,in this paper,both the theoretical study and the experimental study of a 3.4μm mid-infrared pulse train laser pumped by a step-type acousto-optic Q-switched external cavity in MgO:PPLN optical parametric oscillator are carried out.The theoretical model of fundamental frequency step acousto-optic Q-switching is established.The change trends of photon number density at different step intervals are simulated.The optimal trigger time of step signal required for step acousto-optic Q-switching is obtained.The possibility of obtaining pulse train laser output by step acousto-optic Q-switching is determined.In the simulation,the single pulse envelope contains 3 sub-pulse train waveforms.The pulse width of the sub-pulse in the pulse envelope gradually increases,the sub-pulse interval is 5μs,and the pulse envelope repetition frequency is 20 kHz.At the same time,the optimal trigger times for the step signal are obtained to be 16.00,21.00,26.00,50.00μs.The mid-infrared pulse train laser experiment of step acousto-optic Q-switched external cavity pumped MgO:PPLN optical parametric oscillator is carried out,and the 3.4μm mid-infrared pulse train laser output containing three sub-pulses in a single pulse envelope is obtained.The sub-pulse interval is 5μs,the narrowest pulse width is 12.8 ns,and the pulse envelope repetition frequency is 20 kHz,when the maximum average output power is 1.08 W,the maximum optical-to-optical conversion efficiency of 1064 nm fu

关 键 词：中红外激光 脉冲串 台阶声光调Q 光参量振荡器 

分 类 号：TN248[电子电信—物理电子学] TN752