High efficiency tunable unidirectional single-longitudinal-mode Er:YAG ring laser based on an acousto-optic modulator

A wavelength tunable single-longitudinal-mode (SLM) Er:YAG ring laser around 1.6 mu m is demonstrated. By using an acousto-optic modulator (AOM) to force unidirectional operation, up to 10.4 W and 8.7 W SLM laser output power are obtained at 1645.22 nm and 1617.33 nm, with corresponding slope efficiencies of 45% and 40%, respectively. Besides, stable dual-wavelength operation at both 1645 tun and 1617 tun is also achieved with the maximum power of 9.1 W. By rotating the birefringent filter (BRF) in the ring cavity, the wavelength could be tuned from 1616.77 nm to 1617.51 nm and 1644.51 tun to 1646.12 tun. The line width is measured to be 125 kHz at 1617 nm and 131 kHz at 1645 nm via the time-delayed self-heterodyne method. As far as we know, 8.7 W is the highest continuous-wave SLM output power at 1617 nm. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

This study demonstrates a wavelength tunable single-longitudinal-mode Er:YAG ring laser around 1.6 μm, achieving high power and stable dual-wavelength operation with high slope efficiency and small output linewidth.