▎ 摘　　要

We demonstrate a wideband-tunable Q-switched fiber laser exploiting a graphene saturable absorber. We get similar to 2 mu s pulses, tunable between 1522 and 1555 nm with up to similar to 40 nJ energy. This is a simple and low-cost light source for metrology, environmental sensing, and biomedical diagnostics. (C) 2011 American Institute of Physics. [doi:10.1063/1.3552684]