高重复频率飞秒掺镱光纤放大器

 数值分析了掺镱单模光纤放大器的最佳增益光纤长度，并在实验上对掺镱单模光纤放大器和光栅对压缩器进行了研究。以最大平均输出功率为7 mW、重复频率为25.4 MHz、脉宽为56 ps的被动锁模环形腔掺镱光纤激光器作为种子脉冲，用250 mW的976 nm单模半导体激光器分别泵浦3种不同长度的掺镱单模光纤，对种子光进行放大，并用光栅对压缩器对放大后的脉冲在不同光栅距离上进行了压缩实验研究。当掺镱单模光纤长度为1.2 m时得到了较好的放大效果，种子脉冲被放大到140 mW，相应的增益为13 dB，放大后的单脉冲能量为5.5 nJ。在光栅距离为14.1 cm时获得了最短440 fs的脉冲，压缩后的功率为43 mW，相应的峰值功率为3.8 kW。

High repetition rate femtosecond Yb-doped fiber amplifier

The optimum fiber length of the single mode Yb-doped fiber amplifier is simulated.Experiments of the single-mode Yb-doped fiber amplifier and gratings compressor are discussed.The seed pulses come from a mode-locking Yb-doped fiber ring laser.The maximum output average power of the fiber laser is 7 mW at 25.4 MHz repetition rate with a pulse width of 56 ps.The seed pulses are amplified by using three different length single mode Yb-doped fibers respectively which are pumped by a 976 nm semiconductor laser with a maximum output power about 250 mW.The amplified pulses are compressed by using the traditional gratings compressor.When the length of the single mode Yb-doped fiber is 1.2 m,the fiber amplifier generates a maximum power of 140 mW corresponding to a gain about 13 dB.The amplified single pulse energy is 5.5 nJ.When the distance of the gratings is 14.1 cm,the width of the pulses is compressed to about 440 fs which is the minimum.The average power after the compressor is 43 mW corresponding to a peak-power of 3.8 kW.