▎ 摘　　要

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 mu J and 74.6 kHz, respectively.