Passively Q-Switched Tm:CaYAlO 4 Laser Using a MoS 2 Saturable Absorber

We report here for the first time on the diode-pumped continuous-wave laser operation of an a-cut Tm:CaYAlO 4 (CYAO) crystal in a two-mirror laser configuration at about 1850 nm, which is the shortest laser wavelength ever achieved with this material, with a maximum output power of 0.88 W. Using a MoS 2 saturable absorber deposited directly onto the surface of the output coupler, the Tm:CYAO laser is then operated in the Q-switched mode with a maximum output power of 0.49 W and the narrowest pulse width of $0.48~\mu \text{s}$ .