Nanosecond pulse generation at 2.7 μm from a passively Q-switched Er:Y2O3 ceramic laser

Efficient passively Q-switched Er:Y2O3 ceramic lasers operating at 2.7 μm were demonstrated. Using a semiconductor saturable absorber mirror (SESAM) of 2.4% modulation depth, we achieved 63 ns pulses that close to the limit set by the cavity length. For 9.5 W of absorbed pump power, an average output power of 0.88 W was generated with a pulse energy of 17.4 μJ and a pulse duration of 63 ns, resulting a pulse peak power of 0.27 kW. By using a SESAM with a lager modulation depth, shorter pulses of 29 ns were generated. To our knowledge, this is the first report of sub-100 ns pulses from continuously pumped ~3-μm passively Q-switched lasers. The prospects for further pulse shortening are considered, and these results may give a further insight into 3-μm passively Q-switched laser systems.