A Resonantly Pumped 1645 nm Er:YAG Nonplanar Ring Oscillator With 10.5 W Single Frequency Output

Abstract

We demonstrate a single frequency Er:YAG nonplanar ring oscillator (NPRO) resonantly pumped by a fiber laser. Up to 10.5 W single frequency laser output with a slope efficiency of 60.03% was achieved by optimizing the parameters of the Er:YAG NPRO. At 10.5 W output power the $M^{2}$ -factors of the Er:YAG NPRO were 1.09 and 1.24 in the $x$ - and $y$ - directions, respectively. The linewidth of the Er:YAG NPRO was 18.6 kHz.