A graphene-based passivelyQ-switched polycrystalline Er:YAG ceramic laser operating at 1645 nm

Efficient passive Q -switching operation of a 1532 nm in-band pumped polycrystalline Er:YAG ceramic 1645 nm laser is demonstrated in this work. Graphene deposited on a quartz substrate was used as the saturable absorber for the Q -switching operation. Under an incident pump power of 4.14 W, an average output power of 528 mW was obtained, with the pulse energy and pulse repetition rate being 7.08 μJ and 74.6 kHz, respectively.