摘要
研究了在高抽运功率下,单共振光学参量振荡器(SRO)腔型对其输出特性的影响。在理论分析的基础上,实验搭建了基于掺杂氧化镁的周期性极化铌酸锂(MgO∶PPLN)晶体的两镜驻波腔和四镜环形腔SRO。驻波腔SRO的阈值抽运功率为3.2 W,当抽运光功率为14.2 W时,信号光和闲频光功率分别为5.2 W和2.2 W。当抽运光功率大于15 W时,驻波腔SRO输出功率的实测值随抽运光功率的增大而减小,与理论预测偏差较大。环形腔SRO的阈值抽运功率为7.2 W,当抽运光功率为25 W时,信号光和闲频光功率分别为8.1 W和3.6 W。环形腔SRO输出功率的实测值和理论预测基本一致。驻波腔及环形腔SRO输出的信号光在2 h内的功率波动分别优于±2.76%和±2.53%,驻波腔及环形腔SRO输出的闲频光在2 h内的功率波动分别优于±1.24%和±1.19%。驻波腔及环形腔SRO输出信号光的长期频率漂移分别优于±40 MHz及±28 MHz。
Objective 1.5‒1.8μm and 3‒5μm infrared lasers are widely used in free-space optical communication,trace gas monitoring,environmental pollution monitoring,and biomedicine.Infrared lasers can be obtained using quantum cascade,fiber,solid-state,and Raman lasers.Compared with these methods,an optical parametric oscillator(OPO)can be used to achieve an infrared laser with a wider tuning range,higher power,and more stable operation.Based on the resonance of the pump,signal,and idler laser in the OPO cavity,the OPO can be referred to as singly resonant OPO(SRO),doubly resonant OPO(DRO),or triply resonant OPO(TRO).Compared with DRO and TRO,SRO requires only that the signal(or idler)light resonates in the cavity,has a relatively simple design,and no external servo system locking is required to obtain a stable,high-power output.Therefore,the output characteristics of a high-power SRO are investigated in this study.Methods First,a theoretical analysis is conducted on the influence of the SRO cavity length and nonlinear crystal thermal lens effect on the stability of the resonant cavity under standing-wave and ring-cavity structures.To ensure a stable operation of the SRO within significant changes in the resonant cavity parameters,the cavity length corresponding to|(A+D)/2|=0 is selected when the SRO is designed,that is,the standing wave cavity length is 54 mm,and the ring cavity length is 516 mm.According to the focusing factor selected for the SRO cavity,the waist spot of the signal light at the center of the MgO∶PPLN crystal is calculated to be 59.5μm.Subsequently,based on the design of the SRO resonant cavity structure,the laser output characteristics of different SRO cavity types are theoretically analyzed.The theoretical analysis reveals that the pump light in the standing-wave cavity SRO passes through the nonlinear crystal twice;therefore the power gain of the signal light during forward and backward transmission must be considered simultaneously,whereas the pump light in the ring-cavity SRO passes through
作者
聂丹丹
戚蒙
李渊骥
冯晋霞
张宽收
Nie Dandan;Qi Meng;Li Yuanji;Feng Jinxia;Zhang Kuanshou(Department of Physics,Taiyuan Normal University,Jinzhong 030619,Shanxi,China;State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Opto-Electronics,Shanxi University,Taiyuan 030006,Shanxi,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,Shanxi,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2024年第8期176-184,共9页
Chinese Journal of Lasers
基金
国家自然科学基金(62175135)
山西省高等学校科技创新项目(2021L447)。
关键词
非线性光学
单共振光学参量振荡器
连续单频红外激光
高功率
环形腔
nonlinear optics
singly resonant optical parametric oscillator
continuous-wave single-frequency infrared laser
high power
ring cavity
