GHz重复频率亚百飞秒克尔透镜锁模Yb:CaYAlO_(4)激光器  

Sub-100 fs Kerr-lens mode-locked femtosecond Yb:CaYAlO4 laser with GHz repetition rate

作　　者：郑立[1] 田文龙[1] 马骏逸 于洋[3] 徐晓东 韩海年[2] 魏志义[2] 朱江峰[1] Zheng Li;Tian Wen-Long;Ma Jun-Yi;Yu Yang;Xu Xiao-Dong;Han Hai-Nian;Wei Zhi-Yi;Zhu Jiang-Feng(School of Optoelectronic Engineering,Xidian University,Xi’an 710071,China;Beijing National Laboratory for Condensed Matter Physics and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;Academy of Advanced Interdisciplinary Research,Xidian University,Xi’an 710071,China;School of Physics and Electronic Engineering,Jiangsu Normal University,Xuzhou 221116,China)

机构地区：[1]西安电子科技大学光电工程学院,西安710071 [2]中国科学院物理研究所,北京凝聚态物理国家实验室,北京100190 [3]西安电子科技大学前沿交叉研究院,西安710071 [4]江苏师范大学物理与电子工程学院,徐州221116

出　　处：《物理学报》2023年第6期112-118,共7页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2022YFB4601102);国家自然科学基金(批准号:61975071,62105253);西安市科技创新计划(批准号:202005YK01);中央高校基本科研业务费专项资金(批准号:XJS222206)资助的课题.

摘　　要：GHz重复频率飞秒激光具有高单纵模功率和高采样速率等优点,在科学前沿和工业加工等领域具有重要的应用价值.受限于锁模原理和泵浦源的可用功率,GHz重复频率克尔透镜锁模激光器的平均输出功率通常仅为数十到百毫瓦量级,限制了其直接应用.基于此,本文报道了利用高功率单模光纤激光器泵浦的GHz重复频率高功率克尔透镜锁模飞秒激光器.通过合理的腔模设计,构建了四镜环形腔结构,使晶体中激光模式可以和整形后的泵浦光形成良好匹配,以利于软孔克尔透镜锁模的实现.在8 W的泵浦功率下,首次在Yb:CaYAlO_(4)激光器中实现了GHz重复频率的亚百飞秒高功率锁模运转,平均输出功率为2.1 W,重复频率为1.8 GHz,脉冲宽度为88 fs,对应峰值功率大于10 kW.该实验结果表明Yb:CaYAlO_(4)晶体具有产生GHz重复频率高功率飞秒激光的潜力,高功率短脉宽GHz飞秒激光器可为光学频率梳和微加工等领域提供优质光源.Femtosecond lasers with GHz repetition rate play an important role in scientific and industrial applications such as spectroscopy,optical frequency combs and GHz-Burst pulse trains for micro-machining in the ablation-cooled regime.Kerr-lens mode-locked(KLM)technique and passively mode-locking based on semiconductor saturable absorber mirror(SESAM)are the primary methods to generate GHz femtosecond all-solid-state lasers(ASSLs).Kerr-lens mode-locked Ti:Sapphire lasers have made significant progress benefited from the high-power green pump lasers,and repetition rate up to 10 GHz has been obtained with the average power of 1.2 W.In the early 21st century,ytterbium ion(Yb^(3+))doped laser crystals and ceramics with emission wavelengths near 1μm received attention due to their high conversion efficiency and broad gain-bandwidth.Combining the customized SESAM and high-power multimode fiber-coupled laser diodes(LDs),GHz Yb-doped ASSLs with watt-level average power may be easily attained and have made rapid progress.However,GHz KLM lasers have strict requirements for the cavity design and pump sources.For satisfying mode matching and enhancing the soft aperture effect within the gain medium,a high-brightness pump source with excellent beam quality(M^(2)-1)is desired,such as the single-mode fiber coupled LD,however,the maximum pump power of which is only-1W.As a result,the average power of GHz KLM femtosecond laser is typically limited to few tens of milliwatts,which limits the further applications.In this work,we report the first GHz high-power KLM Yb:CaYAlO4 laser by using a high-power single-mode fiber laser instead of the low-power single-mode fiber coupled LDs as the pump source.On the basis of ABCD matrix,a simple four-mirror bow-tie ring cavity is built so that the laser mode can match well with the focused pump spot in the crystal.At the pump power of 8 W,stable unidirectional KLM is achieved,the laser has the average power of 2.1 W with a pulse duration of 88 fs and a repetition rate of 1.8 GHz,corresponding to

关 键 词：激光器 克尔透镜锁模 GHz重复频率 环形腔 

分 类 号：TN248[电子电信—物理电子学]