基于种子脉冲预整形的130μJ线偏振单频12μm纤芯铒镱共掺光纤激光器  

130μJ linear-polarized single-frequency 12-μm-core Er/Yb co-doped fiber amplifier based on pre-shaped seed pulse

作　　者：蒋沛恒 史朝督 付士杰[1,2] 田浩[1,2] 盛泉 史伟[1,2] 沈琪皓[3] 周鼎富[3] 姚建铨[1,2] JIANG Peiheng;SHI Chaodu;FU Shijie;TIAN Hao;SHENG Quan;SHI Wei;SHEN Qihao;ZHOU Dingfu;YAO Jianquan(School of Precision Instrument and Optoelectronics Engineering,Tianjin University,Tianjin 300072,China;Key Laboratory of Optoelectronic Information Technology(Ministry of Education),Tianjin University,Tianjin 300072,China;Southwest Institute of Technical and Physics,Chengdu 610041,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]西南技术物理研究所,成都610041

出　　处：《物理学报》2025年第2期122-128,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:62375201,62275190,62105240);天津市自然科学基金(批准号:23JCQNJC01740);天津大学自主创新基金(批准号:2023XPD-0020);中国兵器工业集团有限公司激光器件技术重点实验室开放基金(批准号:QT23120019);泰山产业领军人才项目(批准号:tscx202312163);光电信息技术教育重点实验室(天津大学)开放基金(批准号:2024KFKT007)资助的课题.

摘　　要：报道了基于种子脉冲预整形实现的百微焦1550 nm线偏振脉冲单频光纤激光器.通过设计三角形脉冲种子波形,优化其前沿上升趋势及低强度持续时间,缓解脉冲激光在放大过程中因增益饱和效应引起的脉冲宽度压缩、激光峰值功率快速增长问题,实现高能量脉冲单频激光放大.实验中基于优化设计的脉冲种子波形,在纤芯直径为12μm的铒镱共掺光纤中,实现了脉冲宽度608 ns、能量130μJ、光谱线宽542 kHz的1550 nm线偏振脉冲单频激光输出.Stimulated Brillouin scattering(SBS)is the major barrier in the process of energy scaling for pulsed single-frequency fiber master oscillator power amplifier(MOPA).Due to gain saturation effect,the laser pulse profile will be gradually distorted with the increase of pump power,which induces steep leading edge and narrower width for the amplified pulses.The resulting laser peak power would increase rapidly and thus the SBS threshold is reached earlier to limit the amplification of pulse energy.A method to obtain high-energy pulsed single-frequency laser by pulse pre-shaping is demonstrated in this work.By designing the leading edge of the triangular pulse,optimizing its rising trend and the duration of the low-intensity rising part,the pulse width compression phenomenon caused by gain saturation is alleviated effectively.Thereafter,the laser peak power increase process can be retarded to reach the SBS threshold so that higher energy can be amplified for the pulsed single-frequency fiber laser.In the experiment,when the seed pulse is optimized to be a triangular pulse with a low-intensity rising edge of 401 ns and a pulse width of 520 ns,a linear-polarized pulse single-frequency fiber laser of 130.9μJ is obtained in a 12-μm-core Er/Yb co-doped polarization-maintaining fiber.The pulse width is broadened to 608 ns at the maximum energy.When it is compared with the triangular pulse seed with a rapidly rising leading edge,its maximum energy is increased by about 25%.The optical signal-to-noise ratio and polarization extinction ratio are measured to be 42 dB and 16 dB at the maximum pulse energy,respectively.The corresponding spectral linewidth measured by a delayed self-heterodyne system is 542 kHz.Higher pulse energy can be anticipated by further optimizing the pulse profile and using large-mode-are gain fibers.

关 键 词：高能量脉冲激光 单频光纤激光器 脉冲预整形 受激布里渊散射效应 

分 类 号：TN248[电子电信—物理电子学]