Green Er3+:YLiF4 upconversion laser at 551 nm with Yb3+ codoping: a novel pumping scheme

We report room-temperature continuous-wave upconversion laser emission on the green transition S-4(3/2) --> (4)I(15/2)in Er(1%), Yb(3%):YLiF4 at 551nm. 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. (C) 1997 Optical Society of Society.