基于可饱和吸收体的700 mW单频2.05μm线性腔铥钬共掺光纤激光器  

700 mW Single-Frequency Linear Cavity Tm^(3+)/Ho^(3+)-Codoped Fiber Laser at 2.05μm Based on Saturable Absorber

作　　者：蒋沛恒 史朝督 陈林 付士杰[1,2] 盛泉[1,2] 付彩玲 史伟[1,2] 姚建铨[1,2] Jiang Peiheng;Shi Chaodu;Chen Lin;Fu Shijie;Sheng Quan;Fu Cailing;Shi Wei;Yao Jianquan(School of Precision Instrument and Optoelectronics Engineering,Tianjin University,Tianjin 300072,China;Key Laboratory of Optoelectronics Information Technology,Ministry of Education,Tianjin University,Tianjin 300072,China;Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province,College of Physics and Optoelectronics Engineering,Shenzhen University,Shenzhen 518060,Guangdong,China)

机构地区：[1]天津大学精密仪器与光电子工程学院,天津300072 [2]天津大学光电信息技术教育部重点实验室,天津300072 [3]深圳大学物理与光电工程学院光电子器件与系统教育部/广东省重点实验室,广东深圳518060

出　　处：《中国激光》2024年第6期9-13,共5页Chinese Journal of Lasers

基　　金：国家自然科学基金(62105240,62275190,62075159,61975146);山东省重点研发项目(2020CXGC010104,2021CXGC010202);天津大学自主创新基金(2023XPD-0020)。

摘　　要：报道了基于掺铥光纤可饱和吸收体的单频2.05μm线性腔铥钬共掺全光纤振荡器。腔内采用4.6 m长的铥钬共掺光纤作为增益介质,并利用未被泵浦的掺铥光纤作为可饱和吸收体实现选频,通过调整可饱和吸收体的长度可优化选频能力。在3.5 W的1570 nm激光泵浦下,获得了最高714 mW的2048.6 nm单频激光输出,相应的斜率效率为25.1%,激光光谱线宽为17 kHz。Objective Single-frequency lasers with wavelengths above 2μm have attracted significant interest because of their numerous applications in areas such as biomedicine,Doppler LiDAR,and space optical communication.Although the power of the fiber master oscillator power amplifier(MOPA)around 2μm has already reached the kilowatt level,the output powers of single-longitudinal-mode(SLM)laser oscillators in this wavelength region are still limited to the hundred-milliwatt level due to the laser gain and frequencyselection approaches.When a piece of unpumped rear-earth doped fiber is found inside the cavity of a laser,the standing wave field inside it results in a dynamic grating because of the Kerr effect.Moreover,the absorption loss of the doped fiber is small under the oscillating longitudinal mode but considerably larger under the side modes.These processes may provide a strong frequency-selection effect,thus allow lasers with longer cavity lengths and resulting higher laser gain to operate in SLM.In this study,we demonstrate an efficient SLM fiber laser at 2050 nm.A piece of Tm^(3+)/Ho^(3+)-codoped fiber is used as gain fiber to provide a laser gain at over 2μm wavelength,while a piece of Tm^(3+)-doped fiber is inserted into the laser cavity as the saturable absorber(SA)for frequency selection.A linear cavity scheme is adopted,rather than the ring cavity usually used in SLM cavity lasers,based on the fiber SA approach to enhance longitudinal mode spacing for a higher power SLM output.A maximum SLM 2050-nm laser output power of 714 mW is obtained under the incident 1570-nm pump power of 3.5 W.Methods A schematic of the SLM laser is given in Fig.1.The gain fiber used is a piece of 9-μm/125-μm Tm^(3+)/Ho^(3+)-codoped fiber with a length of 4.6 m.The pump light launched from a 1570-nm fiber laser is coupled into the core of the active fiber via the filter wavelength division multiplexer 1(FWDM1).Two fiber Bragg gratings(FBGs)are used to make the linear laser cavity.The reflectivity and 3-dB bandwidth of the partiall

关 键 词：激光器 单频光纤激光器 铥钬共掺光纤 可饱和吸收体 2ΜM激光 

分 类 号：TN248[电子电信—物理电子学]