呼吸脉冲锁模的光子晶体光纤飞秒激光器  

Stretched-Pulse Femtosecond Photonic Crystal Fiber Laser

作　　者：宋有建[1] 胡明列[1] 张弛[1] 刘博文[1] 柴路[1] 王清月[1] 

机构地区：[1]天津大学精密仪器与光电子工程学院超快激光研究室,光电信息技术科学教育部重点实验室,天津300072

出　　处：《中国激光》2008年第6期830-834,共5页Chinese Journal of Lasers

基　　金：国家973计划(2003CB314904,2006CB806002);国家863计划(2007AA03Z447);国家自然科学基金(60678012);高等学校博士学科点专项科研基金(20070056083,20070056073);教育部科学技术研究重点项目(108032);教育部新世纪优秀人才支持计划(NCET-07-0597)资助课题

摘　　要：报道了一种掺Yb偏振型大模场面积光子晶体光纤(LMA-PCF)飞秒激光器。作为增益介质的光子晶体光纤的单模场面积比传统光纤高一个数量级,有效地降低了非线性系数,使激光器获得高能量输出。激光器基于线形腔结构,利用半导体可饱和吸收镜实现自启动锁模。光纤激光器利用光栅对进行腔内色散补偿,使其运转在呼吸脉冲锁模状态,即在谐振腔的零色散点附近实现锁模。当腔内净色散呈反常色散时,激光器获得了平均功率为400mW,重复频率为47MHz(对应于8.5nJ的单脉冲能量),脉冲宽度为500fs的稳定的锁模脉冲输出,经腔外色散补偿,脉冲压缩至98fs。当腔内净色散呈正常色散时,激光器输出的单脉冲能量为10.6nJ,脉冲宽度为1.76ps,经腔外色散补偿,脉冲压缩至160fs。A femtosecond fiber laser based on Yb-doped single polarization large-mode-area photonic crystal fiber （LMA-PCF） is demonstrated. The photonic crystal fiber acts as laser gain medium. Since the single mode area of the fiber is an order higher than that of conventional fibers, the fiber nonlinearity is effectively scaled down, and much higher energy laser pulse output is achieved. The laser is based on a linear cavity design, and a piece of semiconductor saturable absorber mirror is used to initiate mode-locking operation. A pair of gratings are used as intracavity dispersion compensation, and the fiber laser operates in the stretched-pulse regime where the amount of net cavity dispersion is in the vicinity of zero. For negative net cavity dispersion, the laser generates 500 fs pulses with an average power of 400 mW at a repetition rate of 47 MHz （corresponding to a single pulse energy of 8.5 nJ）, and the pulses are dechirped to 98 fs after extracavity dispersion compensation. For positive net cavity dispersion, the laser generates 1.76 ps pulses with a single pulse energy of 10.6 nJ, and the pulses are extracavity dechirped to 160 fs.

关 键 词：光纤激光器 光子晶体光纤 呼吸脉冲锁模 大模场面积光纤 

分 类 号：TN248.35[电子电信—物理电子学]