飞秒激光系统相位延迟反射镜的研制

Development of phase delay mirrors for femtosecond laser systems

为了对飞秒激光系统的群延迟色散(group-delay dispersion,GDD)进行调控,设计并制备了相位延迟反射镜。本文系统地研究了相位延迟反射镜补偿群延迟色散原理,使用Nb2O5和SiO2作为高低折射率材料,并采用将相位延迟反射镜与其互补镜配对的方式平缓了群延迟色散曲线,制备出了相位调控数据为-800 fs2的相位延迟反射镜。该反射镜在900~1100 nm范围内的反射率达到99%以上,解决了飞秒激光系统带宽调节的问题,满足飞秒激光器的使用要求。

Phase delay mirrors were designed and prepared to regulate femtosecond laser systems’groupdelay dispersion(GDD).This paper systematically investigates the principle of compensating group-delay dispersion by phase-delay mirrors.Nb2O5 and SiO2 were used as the materials with high and low refractive indices.The group-delay dispersion curves were smoothed out by pairing the phase-delay mirrors with their complementary mirrors.The phase-delayed mirrors with phase modulation data of−800 GDD were prepared,and the reflectivity reached more than 99%in the range of 900 nm−1100 nm.The bandwidth adjustment problem of femtosecond laser systems is solved to meet the requirements of femtosecond lasers.