Large energy, all-fiberized Q-switched pulse laser using a GNRs/PVA saturable absorber

We experimentally demonstrate the use of gold nanorods (GNRs)/PVA composite-deposited side-polished fiber as an efficient saturable absorber for use in an all-fiberized, high-energy Q-switched fiber laser. The modulation depth of the prepared saturable absorber was of ~7.5% at wavelength of 1549.8 nm. Stable Q-switched pulses with a single pulse energy of ~2.56 μJ were readily generated from a fiber Bragg grating-based Fabry-Perot cavity at a pump power of ~229 mW. The pump efficiency was estimated at ~19.2%, and the impact of the variation in the cavity length with respect to the output pulse characteristics was investigated with fixed pump power. The output performance of the proposed all-fiberized laser was compared to that of Q-switched, 1.5-μm fiber lasers incorporating other types of nonlinear optical nanomaterials that had been previously proposed.