Compact Tm:KYW laser passively Q-switched with a PbS-quantum dot-based saturable absorber

摘要

Passive Q switching of lasers with saturable absorbers (SAs) provides a compact and easy-to-use solution to obtain nanosecond pulsed radiation. In the recent years, the advances in the implementation of this approach for fiber and diode-pumped solid-state lasers of 2-µm spectral range were reported [1–3]. Tm³⁺:KY(WO4)2 (Tm:KYW) laser crystal is an attractive material for a gain medium in this spectral range due to its broad fluorescence band and large emission cross-sections. Moreover, it can be pumped by commercially available laser diodes at wavelengths close to 800 nm. It was shown, that glass with PbS quantum dots (QDs) of appropriate size can provide a Q switching of a Tm:KYW laser without intracavity radiation focusing into the SA [2]. Thus, the realization of a miniaturize Q-switched Tm:KYW laser with a short-length cavity using this SA is possible.