摘要
3~5μm波段的窄脉冲高峰值功率的中红外激光在激光雷达、大气环境检测等领域中的实际应用具有重要的研究价值。报道了一种基于声光Q开关和Cr^(4+)∶YAG可饱和吸收体的双调Q泵浦的内腔MgO∶PPLN晶体3.8μm光参量振荡器(OPO)。开展了声光调Q激光器和双调Q激光器泵浦的两种内腔光参量振荡器(IOPO)的实验,当泵浦功率为18.41 W、重复频率为40 kHz时,声光调Q的IOPO输出了脉冲宽度为9.50 ns、峰值功率为1.29 kW的3.8μm闲频光。当泵浦功率为18.41 W,重复频率为40 kHz,插入的Cr^(4+)∶YAG被动Q晶体的小信号透过率为92.67%时,双调Q的IOPO输出了脉冲宽度为6.43 ns、峰值功率为1.48 kW的3.8μm闲频光。实验表明,相较于声光调Q,双调Q内腔OPO输出的闲频光脉冲宽度压缩了32.3%,峰值功率提升了14.7%。同时闲频光的光束质量得到了改善,其横向光束质量因子(M_(x)^(2))和纵向光束质量因子(M_(y)^(2))分别为1.98和2.05。研究结果为窄脉冲宽度、高峰值功率的高质量中红外光源的研发提供了参考。
Objective Mid-infrared lasers with a narrow pulse and high peak power in 3~5μm band have important research value in practical applications in laser communication,lidar,and atmospheric environment detection.Optical parametric oscillators(OPOs)are attracting increasing attention as a common method for fabricating lasers in this band.Currently,the OPO nonlinear crystals used to generate mid-infrared lasers mainly include ZnGeP_(2)(ZGP),AgGaSe_(2)(AGS),and period-polarized LiNbO_(3)(PPLN).Among these,ZGP and AGS crystals have high growth costs and strong absorption of lasers less than 2μm,which is not suitable for pumping with a1μm laser,and PPLN crystals are prone to photorefractive damage at room temperature.Period-polarized LiNbO_(3)doped with MgO(MgO∶PPLN)is the preferred nonlinear crystal for quasi-phase matching,owing to its large nonlinear coefficient,high damage threshold,and wide light transmission range.However,owing to the inherent properties of MgO∶PPLN crystals,the mid-infrared laser obtained using an acousto-optic Q-switched MgO∶PPLN intracavity optical parametric oscillator has a wide pulse width and low peak power,which makes it difficult to meet market demands.To solve these problems,a 3.8μm intracavity optical parametric oscillator(IOPO)with an MgO∶PPLN crystal based on a double Q switching of an acousto-optic modulator and a Cr^(4+)∶YAG saturable absorber is reported in this study.Methods In this study,the pulse width of the mid-infrared laser is significantly compressed,and the peak power and beam quality of the mid-infrared laser are improved.First,based on OPO theory,the polarization period and temperature of the crystal required for the output of the 3.8μm mid-infrared laser by the MgO∶PPLN intracavity optical parametric oscillator are determined.Second,an experiment using an acousto-optic Q-switched MgO∶PPLN intracavity optical parametric oscillator is performed,and the output characteristics of the idler light are measured.Then,we analyze the influence of different small-s
作者
吴淼鑫
金小萍
姚晓岱
刘航
于永吉
刘仲宇
金光勇
Wu Miaoxin;Jin Xiaoping;Yao Xiaodai;Liu Hang;Yu Yongji;Liu Zhongyu;Jin Guangyong(Chongqing Research Institute,Changchun University of Science and Technology,Chongqing 401135,China;Jilin Key Laboratory of Solid Laser Technology and Application,School of Physics,Changchun University of Science and Technology,Changchun 130022,Jilin,China;Shanghai Aerospace System Engineering,Shanghai 201109,China;Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,Jilin,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2024年第14期118-126,共9页
Chinese Journal of Lasers
基金
国家自然科学基金(U20A20214,62275031,11974060)
重庆市自然科学基金(CSTB2022NSCQ-MSX1027)
吉林省教育厅科学技术研究项目(JJKH20230797CY)
吉林省自然科学基金(20210101154JC)。
关键词
中红外激光
声光调Q
双调Q
MgO∶PPLN晶体
光参量振荡器
midinfrared laser
acoustooptic Qswitching
double Qswitching
MgO∶PPLN crystal
optical parametric oscillator
