摘要
3~5μm中红外波段激光在大气中具有较高的透过率,因此被广泛应用于光电对抗等领域。报道了基于掺杂氧化镁的周期极化铌酸锂(MgO∶PPLN)晶体的kHz、mJ量级的中红外光学参量振荡器(OPO)。采用纳秒脉冲1064 nm激光泵浦基于多周期MgO∶PPLN晶体的OPO,OPO采用泵浦双通单谐振平凹腔结构。中红外激光的重复频率为1 kHz,4.08μm处输出的最高单脉冲能量达到1.041 mJ。最高光-光转换效率为16.8%,斜效率为19.3%,中红外激光脉宽约为9.53 ns。在最高能量输出时,OPO运转30 min时输出功率的均方根(RMS)为0.24%。通过温度-极化周期结合的调谐方式,OPO在3.49~4.18μm的较宽范围内都能够保持0.9 W以上平坦的高能量输出。在极化周期27.5~29.6μm以及温度25~200℃的调节范围内,闲频光波长的调谐范围为3.49~4.48μm。实现了重复频率为kHz量级、单脉冲能量为mJ量级的可调谐中红外输出,其在光电对抗领域具有应用价值。
Objective Nanosecond mid-infrared lasers with central wavelengths of 3‒5μm are used in various applications,such as environmental monitoring,LIDAR,and electro-optical countermeasures,owing to the high atmospheric transmission at this band.Thus,developing high-energy mid-infrared laser sources with high pulse repetition frequencies is crucial for practical applications because such lasers exhibit superior jamming effects and can effectively target an opponent’s anti-jamming mechanism.An optical parametric oscillator(OPO)is suitable for efficiently realizing a tunable,high-pulse-repetition-frequency laser owing to its compactness,wide tuning range,and high conversion efficiency.The output characteristics of an OPO are primarily determined by the optical properties of the constituent nonlinear crystals.Among the various nonlinear crystals used in OPOs,periodically poled magnesium-oxide-doped lithium niobate(MgO∶PPLN)has attracted considerable attention because of its large effective nonlinear coefficient,high damage threshold,and flexible phase matching ability.However,to date,a pulse energy of the order of hundred microjoules has been realized for PPLN-OPOs with high pulse-repetition frequencies.In this study,a kilohertz-and millijoule-level mid-infrared OPO based on an MgO∶PPLN crystal is developed.The OPO,which is pumped by a 1064-nm nanosecond pulsed laser based on multi-period MgO∶PPLN with a double-pass single-resonance structure and flat-concave cavity,delivers a high output energy of up to 1.041 mJ at 4.08μm with a pulse repetition frequency of 1 kHz.Subsequently,the output energy of the high-pulserepetition-frequency mid-infrared OPO based on a PPLN crystal is increased to mJ range,which is suitable for mid-infrared electrooptical countermeasure applications.Methods The output energy of a mid-infrared laser with a high pulse-repetition frequency is significantly increased.First,the OPO is pumped by a high-performance,high-pulse-repetition-frequency 1064-nm laser with a double-pass single-resonan
作者
刘帅
陈锴
孙悦
闫超
乔鸿展
常继英
李吉宁
王与烨
钟凯
徐德刚
姚建铨
Liu Shuai;Chen Kai;Sun Yue;Yan Chao;Qiao Hongzhan;Chang Jiying;Li Jining;Wang Yuye;Zhong Kai;Xu Degang;Yao Jianquan(College of Precision Instrument and Opto-Electronics Engineering,Tianjin University,Tianjin 300072,China;Key Laboratory of Optoelectronics Information Technology,Ministry of Education,Tianjin University,Tianjin 300072,China;Key Laboratory of Micro Opto-electro Mechanical System Technology,Tianjin University,Ministry of Education,Tianjin 300072,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2024年第7期227-233,共7页
Chinese Journal of Lasers
基金
国家自然科学基金(62175182,62275193,U22A20123,U22A20353)。
