激光与光电子学进展, 2014, 51 (3): 031404, 网络出版: 2014-03-03
腔镜对掺铥光纤激光器输出性能的影响
Cavity Mirrors Influence on Thulium-Doped Fiber Lasers Output Performance
摘要
由于2 mm 激光处于人眼安全区和大气的弱吸收带,因此掺铥光纤激光器受到了广泛关注。比较了掺铥双包层光纤在激光二极管(LD)抽运时后端分别采用平面镜和凹面镜下激光器输出功率特性。实验和理论表明,由于光纤端面和平面反射镜之间存在着间隙、倾斜以及光纤端面存在缺陷等因素,使得激光腔的损耗增大,激光器输出性能受到严重影响。根据波动理论分析了光纤后端面分别采用平面反射镜和凹面反射镜下谐振腔插入损耗特性,理论表明采用凹面反射镜时谐振腔损耗要比采用平面反射镜时小。光纤后端的腔镜采用凹面镜时,获得最大输出功率为22 W,对应的中心波长为1998.6 nm,相对于入射抽运光功率的斜率效率为43%的激光输出。相比采用平-平腔的激光器其斜率效率提高了10%,镜面承受的热损伤得到大幅缓解。
Abstract
As 2 mm laser is in eye-safe areas and weak atmospheric absorption band, thulium-doped fiber laser attracts a lot of attentions. The lasers output power characteristics of thulium- doped double- clad fiber under laser diode (LD) backward pumping using a plane mirror and concave mirror are compared. Experiments and theories suggest that the laser cavity losses increase because the gap, tilt, and fiber end face defects between the fiber end face and the plane mirror and mirror thermal damage and other factors, and the laser output performance is severely affected. The cavity insertion loss properties are analyzed after using a plane mirror and concave mirror respectively at the end of the fiber based on the wave theory, which suggests that using a concave mirror cavity the loss is smaller than that using a plane mirror. When using the concave mirror cavity structure after fiber end, the maximum output power of 22 W is obtained, corresponding to the center wavelength of 1998.6 nm and the slope efficiency of 43% relative to the incident pump power. Comparing to the use of plane mirror cavity the laser slope efficiency increases of 10% , and the thermal damage of mirror is alleviated obviously.
刘正涛, 郑义. 腔镜对掺铥光纤激光器输出性能的影响[J]. 激光与光电子学进展, 2014, 51(3): 031404. Liu Zhengtao, Zheng Yi. Cavity Mirrors Influence on Thulium-Doped Fiber Lasers Output Performance[J]. Laser & Optoelectronics Progress, 2014, 51(3): 031404.