用半导体可饱和吸收镜实现侧面抽运Nd:YAG被动锁模固体激光器

利用半导体可饱和吸收镜(SESAM)锁模技术实现的超快脉冲激光器具有结构简单紧凑、脉冲序列稳定等优点,在许多领域有着重要用途。简述了用半导体可饱和吸收镜锁模固体激光器的具体要求及方案,介绍了采用Z型折叠腔结构和大功率侧面抽运模块实现的半导体可饱和吸收镜被动锁模Nd:YAG固体激光器。得到了平均功率为4.7 W,脉冲重复频率55 MHz,单脉冲能量85 nJ的皮秒激光脉冲,光束质量好,M2因子约为1.2,谱线宽度约为0.1 nm,在小时间尺度上得到较好的锁模效果,对实验现象进行了描述,对实现高功率侧面抽运锁模激光器进行了初步探讨。

Passively Mode-Locked Side-Pumped Nd:YAG Laser with Semiconductor saturable Absorption Mirrors

Semiconductor saturable absorption mirrors (SESAMs) have become the important components in the compact mode-locking solid-state lasers. we designed a side-pumped folded cavity Nd:YAG solid laser mode-locking with SESAM and got the highest average output power of about 4.7 W. The single pulse has about 85 nJ energy and 55 MHz repeat frequency. The spectrum is measured and the full wavelength at half maximum (FWHM) is about 0.1 nm, and the M2 factor is about 1.2. Significantly, with exactly measurement about the thermal focus length, special cavity can be designed to control the mode radius. Although the laser was pumped by high power LDs (over hundreds watts), but it still has very well beam quality(nearly the diffraction-limited beam). From this work, it get closer towards the high power mode-locking solid laser.