Stable Q-Switched Mode-Locking of 2.7 μm Er:Y2O3 Ceramic Laser Using a Semiconductor Saturable Absorber

This paper studies synchronous Q-switch and mode-locking of an 2.7 μm Er:Y2O3 ceramic laser pumped with a high brightness 976 nm fiber laser and using a semiconductor saturable absorber mirror. The Er:Y2O3 ceramic is home-developed with Er3+ doping concentration of 7 at.%. The laser generated ~92 mW of average output power with stable mode-locked pulses of 100% modulation depth and 130 MHz repetition rate embedded inside Q-switched envelopes of ~1.2 μs width. Repetition rates of the Q-switched pulse envelopes are tunable from 5.1 kHz to 29 kHz with the width varying from 2.7 μs to 1.2 μs.