亚纳秒脉宽的Tm:GdVO_(4)被动锁模激光器  

Passively Mode-Locked Tm∶GdVO_(4) Laser with Sub-Nanosecond Pulse Width

作　　者：周伟杰 纳全鑫 王瑀 许长文 范滇元[1] Zhou Weijie;Na Quanxin;Wang Yu;Xu Changwen;Fan Dianyuan(International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology,Shenzhen University,Shenzhen 518060,Guangdong,China;Pengcheng Laboratory,Shenzhen 518060,Guangdong,China)

机构地区：[1]深圳大学二维材料光电科技国际合作联合实验室,广东深圳518060 [2]鹏城实验室,广东深圳518060

出　　处：《中国激光》2023年第22期22-27,共6页Chinese Journal of Lasers

基　　金：广东省自然科学基金(2019A1515111206);深圳市科技计划项目(JCYJ20190808145016980)。

摘　　要：报道了一种1.85μm亚纳秒脉宽的Tm:GdVO_(4)被动锁模激光器。通过使用商用半导体可饱和吸收镜(SESAM)和高透过率的输出耦合镜(OCs),实现了Tm:GdVO_(4)短波段、亚纳秒脉宽的激光输出。对于连续波(CW)运转,当使用透过率分别为10%、20%和30%的不同OCs时,激光输出功率均超过1 W,在1844、1850、1851、1861、1865 nm波长上分别产生了激光振荡。对于连续波锁模(CWML)运转,通过使用上述不同OCs,均实现了稳定的输出,工作波长均位于1851.6 nm附近,光谱宽度始终不高于光谱仪0.05 nm的分辨率,输出脉宽分别为474、752、651 ps。其中,当使用透过率为30%的OC时,可实现320 mW的最大平均输出功率。Objective Laser sources possessing sub-nanosecond pulse widths,such as mode-locked lasers,have garnered significant attention owing to their wide-ranging applications in fields such as medical cosmetology,lidar,archaeological bone cleaning,engine ignition,and pumping optical parametric oscillators(OPOs)for mid-infrared lasers.The generation of laser pulses possessing sub-nanosecond widths is generally achieved through passively Q-switched microchip lasers or actively mode-locked lasers.However,in the case of the latter,a repetition rate of approximately 100 MHz-level is attained,necessitating the use of an acousto-optic or electro-optic modulator,which renders the system complicated.On the other hand,the former method achieves high peak power but only offers a repetition rate at the kilohertz level.Thus,there exists a need to explore the use of passively mode-locked lasers possessing narrow laser spectrums,which can generate laser pulses possessing sub-nanosecond widths and high repetition rates.Methods The experimental setup is shown in Fig.1.The pump source is a fiber-coupled laser diode(LD)at 793 nm,with the maximum output power of 30 W,the numerical aperture of 0.22,and the core diameter of 105μm.The pump spot diameter is approximately 168μm in the center of the Tm∶GdVO_(4) crystal,which is transformed by lens f1(focal length f=50 mm)and f2(f=80 mm).A Tm3+∶GdVO_(4) crystal with size of 3 mm×3 mm×4 mm is used as the gain medium,and both surfaces of this crystal are antireflection(AR)for the pump and laser wavelengths.The crystal is enclosed with indium foil and fixed onto a copper heat sink,which is kept at a temperature of 18℃using a water chiller.To achieve mode-locking,a semiconductor saturable absorption mirror(SESAM),three plane mirrors,and three curved mirrors are employed to construct a resonator with a cavity length of 2487 mm,corresponding to a repetition rate of 60.3 MHz.M1 and M2 are coated with high reflectivity(HR)films at 1.8-2.0μm and high transmission films at 793 nm pump light,respe

关 键 词：激光器 固体激光器 被动锁模 半导体可饱和吸收镜 亚皮秒 二极管泵浦激光器 Tm:GdVO_(4)激光器 

分 类 号：TN248.1[电子电信—物理电子学]