LAUSR

A 1550 nm Q-switched fiber laser using a carbon platinum saturable absorber deposited on side-polished fiber (SPF) is proposed and demonstrated. The SPF is approximately 2 mm with a polarization-dependent loss (PDL) of 0.4 dB and an insertion loss of 2.5 dB. A stable Q-switched output spectrum is obtained at 1559.34 nm with a peak power of ～6 mW, a pulse width of 1.02 μs, pulse energy of 5.8 nJ, average output power of 0.76 mW, and a repetition rate of 131.6 kHz taken at a pump power of 230.0 mW. A signal-to-noise ratio of 49.62 dB indicates that the Q-switched pulse is highly stable.