▎ 摘　　要

Nonlinear transmission parameters of monolayer graphene at 1645 nm were obtained. Based on the monolayer graphene saturable absorber, a 1532 nm LD pumped 1645 nm passively Q-switched Er:YAG laser was demonstrated. Under the pump power of 20.8 W, a 1645 nm Q-switched pulse with FWHM of 0.13 nm (without the use of etalon) and energy of 13.5 mu J per pulse can be obtained. To the best of our knowledge, this is the highest pulse energy for graphene-based passively Q-switched Er: YAG laser operating at 1645 nm, suggesting the potentials of graphene materials for high-energy solid-state laser applications. (C) 2014 Optical Society of America