Green Er\u3csup\u3e3+\u3c/sup\u3e:YLiF4 upconversion laser at 551 nm with Yb\u3csup\u3e3+\u3c/sup\u3e codoping: A novel pumping scheme

We report room-temperature continuous-wave upconversion laser emission on the green transition 4S3/2 → 4I15/2 in Er(1%),Yb(3%):YLiF4 at 551 nm. Green laser operation was obtained for titanium-sapphire pump wavelengths continuously tunable between 955 and 974.5 nm. Codoping with Yb3+ resulted in a more efficient excitation of the upper laser level by upconversion processes. The maximum green laser output power was 37 mW at an incident titanium-sapphire pump power level of 1580 mW at 966 nm. © 1997 Optical Society of America