1.86 W cw single-frequency 1319 nm ring laser pumped at 885 nm

A 1.86 W cw single-frequency 1319 nm laser was produced by using an 885 nm-pumped Nd:YAG crystal with a compact four-mirror ring cavity, for the first time to our knowledge. The Nd: YAG produced a slope efficiency of 21% and an optical-to-optical efficiency of 18% with respect to the absorbed diode pump power. A near-diffraction-limited beam with M-2 = 1.2 was achieved under the maximum output power. (C) 2012 Optical Society of America