Diode pumped 2.79 μm Er3+:Cr3+:YSGG laser

In this paper, we report on lasing at 2.79 μm under 974 nm diode laser excitation in an Er:YSGG crystal codoped with chromium. The host is YSGG, an Y₃Sc₂Ga₃O₁₂ crystal. The present Cr³⁺:Er³⁺: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^-1. Therefore, 54.2% of the incident pump power is absorbed in the crystal. The 2.79 μm radiation occurs from the transition of ⁴I₁₁2/ to ⁴I₁₃2/ in Er³⁺. The best absorption of the Er³⁺ 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.