以单脉冲能量更高的孤子激光器为种子源,通过主振荡放大技术,获得了2μm波段的高功率、皮秒脉冲激光器.该种子源是一个被动锁模的光纤激光器,通过优化、管理激光器谐振腔内的色散,获得了脉冲宽度为50ps、重复频率为55.6 MHz、谱宽约为21nm的高能量孤子脉冲输出.利用单模光纤在2μm波段的负啁啾色散特性,在进行功率放大之前将作为种子源的激光脉冲宽度展宽至600ps.最后,经过两级放大之后,获得平均功率约23 W、脉宽为660ps的激光输出.利用光栅对,对放大后的激光脉冲进行压缩,经测试压缩后的脉冲宽度约为0.9ps.
Thulium-doped fiber Master Oscillator Power Amplifier(MOPA)was demonstrated for high power picosecond laser within the 2μm wavelength range with a high energy soliton seed.The master oscillator was a passively mode-locked fiber laser,which can generate high energy soliton pulses with 50 ps pulse width,a repetition frequency of 55.6 MHz and a spectral width of~21nm by managing and optimizing its dispersion.The seed pulse was stretched to ~600ps by a spool of passive fiber with anomalous dispersion before sent to two amplified stages.Finally,average power of about 23 W and pulse duration of 660 ps were achieved before the pulse compressor.With a grating-pair compressor,the chirped pulse can be compressed to about 0.9ps.