Efficient acousto-optically Q-switched compact Yb:KLuW laser with self-Raman conversion

Abstract

We report, for the first time to our knowledge, on acousto-optically Q-switched operation of a compact Yb:KLu(WO4)2 crystal laser, demonstrated at pulse repetition frequencies ranging from 60 kHz down to 3 kHz. 5.03 W of average output power at 1040.2 nm was produced at 60 kHz, with optical-to-optical and slope efficiencies of 50% and 62%. Self-Raman conversion was realized at pulse repetition frequencies not higher than 50 kHz; a maximum Stokes output power of 0.25 W at 1138.2 nm was generated at 20 kHz while the fundamental output power reached 2.20 W, the self-Raman conversion efficiency was determined as 6.0%. The resulting Raman pulse energy, duration, and peak power were, respectively, 12.5 μJ, 2.1 ns, and 6.0 kW.