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 fundamental light and 3.4μm parametric light is 10.05%,and the beam quality factor M2 is 2.01.The output position of the sub pulses in each repetition period in the experiment is basically consistent with the simulation result,and it is found in both simulation and experiment that the width of the sub pulses within each pulse envelope gradually increases.The experimental results show that 3.4μm mid-infrared pulse train laser output can be obtained by using step AOQS combined with OPO.This innovative method provides theoretical and technical support for detecting atmospheric pollutant concentration by using mid-infrared pulse train laser.
作者
姚晓岱
吴爽
赵锐
吴淼鑫
刘航
金光勇
于永吉
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)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
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.
关键词
中红外激光
脉冲串
台阶声光调Q
光参量振荡器
mid-infrared laser
pulse train
step acousto-optic Q-switching
optical parametric oscillation
