Kilo-hertz-level Q-switched laser characteristics of a Tm,Y:CaF_2 crystal

Employing an acousto-optic modulator (AOM), the Q-switched laser characteristics of a Tm,Y:CaF2 crystal have been investigated. With T = 1%, 2% and 5% output couplers (OCs), output laser performance in both continuous-wave (CW) and Q-switching regimes have been presented and are discussed in details. The AOM Q-switched Tm,Y:CaF2 laser can run at high repetition rates ranging from 1 kHz to 10 kHz. Under the modulation frequency of 1 kHz, pulses with the shortest duration of 280 ns and the maximum pulse energy of 0.335 mJ have been delivered, corresponding to a maximum peak power of 1.19 kW. The results indicate that Tm,Y:CaF2 crystals can act as a promising candidate of gain medium for pulsed 2 μm laser.