2.3W双向抽运3.5μm光纤激光器  

2.3W 3.5μm Fiber Laser Based on Bidirectional Pumping

作　　者：张新[1] 佟存柱[1] 蔡凯迪 王延靖 汪丽杰[1] 田思聪[1] Zhang Xin;Tong Cunzhu;Cai Kaidi;Wang Yanjing;Wang Lijie;Tian Sicong(State Key Laboratory of Luminescence and Applications,Changehun Imstitute of Optics Fine Meehamics and Prysics Chinese Academy of Seiences,Chamgehun 130033 Jilin,China;Colege of Materials Seience nd Opto-Eletronic Tehnology Umiversit of Chinese Academ of Seience Beijing 100049,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所发光学及应用国家重点实验室,吉林长春130033 [2]中国科学院大学材料科学与光电技术学院,北京100049

出　　处：《中国激光》2022年第18期1-6,共6页Chinese Journal of Lasers

基　　金：国家自然科学基金(61790584,61774153);发光学及应用国家重点实验室自主课题(SKLA-Z-2021-07);中国科学院青年创新促进会项目(2018249)。

摘　　要：功率低是限制中红外光纤激光器实际应用的一个关键因素,功率提升对于拓展其应用范围具有非常重要的意义。报道了2 W级近单模3.5μm光纤激光实验装置,即采用976 nm和1973 nm两个波长的泵浦光源级联泵浦铒掺杂氟化物光纤(Er∶ZBLAN),实现了3.5μm激光输出。为了进一步提升激光输出功率,采用双向抽运方法,最终实现的室温下连续输出的最高功率为2.32 W。激光激射阈值约为1.5 W,激光器工作时总的光光转换效率为10.33%,中心波长为3.54μm,激光器工作模式为近单模,光束质量因子(M^(2))小于1.5。Objective There is an increasing scientific interest in developing mid-infrared laser sources to fulfill various application requirements in the biomedical,defense and security,and material processing.In particular,the 3.5μm fiber laser has become a research hotspot due to its good beam quality,high brightness,and being in an atmospheric window.Limited by the nature of fiber materials and lack of fiber optical devices,the power of a mid-infrared fiber laser is two to three orders of magnitude less than that of a near-infrared laser.However,the low power of a mid-infrared fiber laser is a key factor limiting its practical applications.It is great significance for expanding its application fields to improve the power of a mid-infrared fiber laser.Methods The method of cascade pumping is proposed to achieve a high efficiency 3.5μm fiber laser.The 1973 nm and 976 nm dual-wavelength laser source is used to pump the Er-doped fluoride fiber(Er∶ZBLAN).The ground-state particles are pumped by the 976 nm laser to the energy level of ^(4)I_(11/2),and the particles at the ^(4)I_(11/2) energy level are pumped by the 1973 nm laser to the upper energy level to achieve a 3.5μm laser.However,the end of a fiber would be damaged under a high pump power.Considering that the main factor of the 3.5μm laser power is the 1973 nm pump power,the bidirectional pumping scheme is proposed to improve the output power here.Double homemade 1973 nm pump laser sources are coupled into the 4.8 m long Er∶ZBLAN fiber.The core diameter and numerical aperture of the fiber are 17.8μm and 0.12,the cladding diameter and numerical aperture are 250μm and 0.5,and the doping concentration(mole fraction)is 1%.Both ends of the optical fiber are cut into a 0°angle and closely attached to the cavity mirror.The reflectivity of the output coupling mirror is about 60%at 3500 nm(high transmission@1973 nm&high transmission@976 nm).And a 45°dichroic mirror DM^(2)(high reflection@3500 nm&high transmission@1973 nm&high transmission@976 nm)is used to output a

关 键 词：激光器 中红外激光 光纤激光 双向泵浦 氟化物光纤 

分 类 号：TN248.1[电子电信—物理电子学]