功率4.1 W,脉宽48 fs,重复频率74 MHz的掺钛蓝宝石飞秒激光振荡器  

Ti∶Sapphire Femtosecond Laser Oscillator with power of 4.1 W,pulse width of 48 fs,and repetition rate of 74 MHz

作　　者：刘滋润 陈兴进 王楠[1,2,3] Liu Zirun;Chen Xingjin;Wang Nan(College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,Guangdong,China;Shenzhen Key Laboratory of Laser Engineering,Shenzhen University,Shenzhen 518060,Guangdong,China;Key Laboratory of Optoelectronic Devices and Systems of the Ministry of Education,Shenzhen University,Shenzhen 518060,Guangdong,China)

机构地区：[1]深圳大学物理与光电工程学院,广东深圳518060 [2]深圳大学深圳市激光工程重点实验室,广东深圳518060 [3]深圳大学光电子器件与系统教育部重点实验室,广东深圳518060

出　　处：《中国激光》2023年第22期7-13,共7页Chinese Journal of Lasers

基　　金：深圳市科技创新项目(20200810161702001);深圳市孔雀计划高端人才启动项目。

摘　　要：基于克尔透镜锁模机制,实现了掺钛蓝宝石飞秒激光振荡器的高平均功率和短脉宽输出。使用功率为16 W、波长为532 nm的连续光进行泵浦,使用高折射率的棱镜对进行色散补偿,同时使用狭缝辅助锁模,实验获得了平均输出功率为4.1 W、脉冲宽度为48 fs、重复频率为74.15 MHz的飞秒脉冲。相比当前同类型激光器参数(20 W泵浦光下输出功率为4 W,脉宽为130 fs,重复频率为76 MHz的飞秒激光),功率提升了2.5%,光-光转换效率提高了28%,脉宽缩短了63%,峰值功率提升了2.8倍。Objective In order to obtain a good light-matter interaction effect,it is usually required laser has the characteristics of high power and short pulse duration to obtain a strong peak power and improved time resolution.The ultrawide gain bandwidth and high thermal conductivity of the Ti∶sapphire crystal make it a good gain medium.However,because of the power limitations of the pump source,the thermal lens effect,and the mode-locked pulse stability,it is difficult to increase the average output power of the Ti∶sapphire femtosecond laser.Therefore,Ti∶Sapphire femtosecond lasers with high average power,short pulse width,and high repetition rate have always been a research hotspot in ultrafast lasers and their applications.Methods The experimental setup is shown in Fig.1.A continuous-wave green laser with a maximum output power of 16 W at 532 nm is used as a laser pump.The 150 mm plano-convex lens is used to concentrate the pump light onto the Ti∶sapphire crystal.The crystal is mounted on a water-cooled copper crystal frame and wrapped in an indium foil.The water temperature is regulated at 14℃±0.1℃ using a water cooler with a cooling capacity of 600 W.Concave mirrors C1 and C2 have a curvature radius of 150 mm,a folding angle of 24°,and exhibit strong reflection in the spectral region of 750-850 nm.Flat mirrors M1-M4 exhibit strong spectral reflections in the 750-850 nm range.The output coupling mirrors(OC)have a transparency of 20%.P1 and P2 are a pair of prisms used to compensate for intracavity dispersion,and their separation is fixed at 340 mm.The total length of the resonator is 2.02 m.Unlike commercial laser oscillators in which a slit is placed at the end mirror to suppress high-order transverse modes,we position an adjustable slit in the optical path between the prism pair,which suppresses the high-order transverse mode in the cavity and selectively suppresses the continuous wave(CW)component at a specific spectrum when the high-power laser in the cavity is running.A lens with an extended focal

关 键 词：激光器 高平均功率 克尔透镜锁模 飞秒激光 掺钛蓝宝石 

分 类 号：TN248[电子电信—物理电子学]