Mid-Infrared Dual-Wavelength Passively Q-Switched Er: SrF₂ Laser by CsPbCl₃ Quantum Dots Absorber

A passively Q-switched compact dual-wavelength Er: SrF2 laser, operating at a 2729.73 nm and 2747.2 nm wavelength, was demonstrated by utilizing CsPbCl3 quantum dots (QDs) as a saturable absorber (SA). The maximum average output power with the shortest duration of 510 ns and a repetition rate of 45 kHz was achieved at 190 mW, and the corresponding maximum single pulse energy and the peak power were 73.69 mu J and 141.7 W, respectively. The results present an efficient dual-wavelength laser source, and the halogen perovskite quantum dot has the potential to be employed as an excellent saturable absorber in mid-infrared pulsed solid-state lasers.