SESAM无损伤运转的大功率高重复频率皮秒激光器

High-Power and High Repetition-Rate Picosecond Laser with No Damage in SESAM

提出一种可实现大功率输出、重复频率为80 MHz的皮秒锁模振荡器,当抽运功率为22.4 W时,可实现功率为5.1 W,频谱信噪比大于60 d B,脉冲宽度为23.7 ps的皮秒脉冲的稳定输出。通过选择合理的半导体可饱和吸收镜(SESAM)参数和合适的腔型,实现SESAM长期无损伤运转并进行500 h的实验验证。采用888 nm激光二极管(LD)端面抽运Nd∶YVO4晶体的两级功率放大系统将皮秒锁模振荡器的功率提升至44 W。放大系统的光-光转换效率大于25%,输出光具有良好的光斑模式,光束质量因子M2<1.5。

A high-power picosecond mode-locked Nd∶YVO4laser system with high repetition-rate of 80 MHz is reported. When the pump power is 22.4 W, the oscillator provides the output power of 5.1 W with signal-tonoise ratio more than 60 d B and a pulse duration of 23.7 ps. The semiconductor saturable- absorber mirror（SESAM） of oscillator can work for more than 500 h without any damage by selecting reasonable SESAM parameters and suitable cavity. The power is amplified to 44 W by two stages of power amplifier end-pumped by a continuous- wave 888 nm laser diode（LD）. Optical- optical conversion efficiency of amplified system is more than 25%. The beam quality factor M2 after amplification is less than 1.5.