飞秒激光在双折射微结构光纤中模式控制的四波混频效应的实验研究  

Mode-controlled four-wave-mixing in the birefringent microstructure fiber by femtosecond laser pulses

作　　者：胡明列[1] 王清月[1] 栗岩峰[1] 王专[1] 柴路[1] 张伟力[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(天津大学),天津300072

出　　处：《物理学报》2005年第9期4411-4415,共5页Acta Physica Sinica

基　　金：国家重点基础研究专项基金(批准号:G1999075201;2003CB314904);国家自然科学基金(批准号:60278003);国家高技术研究发展计划(批准号:2003AA311010)资助的课题.~~

摘　　要：利用飞秒激光脉冲在长度为10cm,包层具有大空气比的双折射微结构光纤中通过高阶模相位匹配的四波混频获得了波长可调谐的反斯托克斯波.实验中脉冲宽度为35fs,中心波长820nm,单脉冲能量4nJ的飞秒激光脉冲耦合到长轴直径为5μm,短轴为4.6μm的双折射微结构光纤中.在高阶模传输情况下,通过调制耦合光的偏振方向,获得了具有不同中心波长的反斯托克斯波.通过对比分析,讨论了输入光的偏振态对双折射微结构光纤中高阶模式下四波混频效应的影响情况.理论计算分析很好的解释了实验结果.Birefringent microstructure fibers are shown to allow efficient gereration of anti-Stokes line emission as a result of four-wave- mixing in higher mode by using unamplified femtosecond Ti ： sapphire laser pulses. Intense blue-shifted lines with different central wavelength were generated in the high-delta （i. e. high-air filling in the cladding） microstructure fiber with axis sizes 5.0 and 4.6 μm by femtosecond laser pulses with 35-fs in duration, 820nm in central wavelength and 4nJ in energy per pulse. The experimental result shows that phase-matched four-wave mixing in higher-order modes of microstructure fibers allows unprecedentedly high efficiencies of anti-Stokes frequency conversion to be achieved for subnanojoule femtosecond laser pulses. The dependence factor of the four waves mixing in birefringent microstructure fiber is compared and analyzed. Good agreement between the theory and experiment is achieved.

关 键 词：微结构光纤 飞秒脉冲激光 四波混频 模式控制 双折射 实验 斯托克斯波 中心波长 波长可调谐 

分 类 号：TN24[电子电信—物理电子学] TP393.1[自动化与计算机技术—计算机应用技术]