EFFICIENT DIODE-PUMPED SINGLE-FREQUENCY ERBIUM-YTTERBIUM FIBER LASER

We report a 7.6-mW single-frequency fiber laser operating at 1545 nm, using for the first time an Er3+:Yb3+ doped fiber and a fiber grating output coupler. The laser did not exhibit self-pulsation, which is a t ypical problem in short three-level fiber lasers, and had a relative i ntensity noise (RIN) level below -145.5 dB/Hz at frequencies above 10 MHz. The linewidth of the laser was limited by the relaxation oscillat ion sidebands in the optical spectrum and was typically less than 1 MH z.