报道了一种基于大模场光子晶体光纤放大的高峰值功率飞秒脉冲激光系统。该激光器系统采用光纤啁啾脉冲放大结构,种子源采用重复频率为40 MHz,脉冲宽度为500 fs,输出功率为10 mW的光纤激光器。利用体布拉格光栅(VBG)将脉冲展宽至500 ps,经过多级放大并利用声光调制器降频为500 kHz,然后采用大模场纤芯直径为40 μm和85 μm光子晶体光纤作为功率放大器,最后采用VBG压缩脉宽至767 fs,得到平均功率为104 W的激光输出,其中心波长为1030 nm,实现了峰值功率为0.271 GW的近衍射极限激光功率输出。

An ultrashort pulse laser system based on ultra-large-mode-field fiber amplification is reported. The laser system adopts fiber chirped pulse amplification amplification structure. The pulses with 500 fs are stretched to 500 ps by volume Bragg grating (VBG). The seed laser with average output power of 10 mW and repetition of 40 MHz is amplified by Yb-doped fiber amplifier. The repetition is adjusted to 500 kHz through the acousto-optic modulator. Then we use the large-mode field core diameters of 40 μm and 85 μm photonic crystal fibers as power amplifiers. Finally the laser with center wavelength of 1030 nm is compressed by VBG. The average output power is 104 W, and the near-diffraction-limit 767 fs pulse with maximum peak power of 0.271 GW is achieved.