919.8 nm self-Q-switched Nd-doped silica all-fiber laser

A compact self-Q-switched Nd-doped silica all-fiber laser near 920 nm is experimentally demonstrated for the first time. Under an 808 nm laser diode (LD) pumping, a pair of homemade cavity mirrors that include a fiber Bragg grating (FBG) and a fiber end-facet mirror (FM) construct a compact and simple all-fiber resonator. A piece of 2.8-m-long Nd-doped silica fiber not only provides an optical gain, but also functions as a saturable absorber (SA). Stable Q-switching operation was successfully achieved. The pulses of 919.8 nm are generated at a threshold of 90 mW, and the maximum average power obtained is 8.56 mW with a pulse width of 1.62 μs and a repetition rate of 72.03 kHz. And especially, a single pulse energy of 123.4 nJ is realized. To the best of our knowledge, this work represents the first compact Q-switched Nd-doped silica all-fiber laser operating at 919.8 nm, and the highest pulse energy is highlighted in the pulsed Nd-doped all-fiber lasers.