Diode pumped 2.79 /spl mu/m Er/sup 3+/:Cr/sup 3+/:YSGG laser

In this paper, we report on lasing at 2.79 /spl mu/m under 974 nm diode laser excitation in an Er:YSGG crystal codoped with chromium. The host is YSGG, an Y/sub 3/Sc/sub 2/Ga/sub 3/O/sub 12/ crystal. The present Cr/sup 3+/:Er/sup 3+/:YSGG crystal is grown by the Czochralski method at the Institute of General Physics in Moscow. The crystal has a thickness of 3 mm and its absorption coefficient at 974 nm is 2.6cm/sup -1/. Therefore, 54.2% of the incident pump power is absorbed in the crystal. The 2.79 /spl mu/m radiation occurs from the transition of /sup 4/I/sub 11/2/ to /sup 4/I/sub 13/2/ in Er/sup 3+/. The best absorption of the Er/sup 3+/ ions is at 976 nm. The laser threshold is about 0.5 W and increases with a rising pump wavelength. The slope efficiency is 3.4 %. The resonator configuration is by no means optimized.