Er:YAlO 3 upconversion laser

Upconversion laser emission at 550 nm is reported for Er:YAlO3. Lasing was produced using both sequential two step pumping and cross relaxation energy transfer. In addition, photon avalanche upconversion pumping was demonstrated. Selection among these pumping mechanisms is determined by the pump wavelength, and laser operation was obtained with excitation between 785 nm and 840 nm. The highest laser output power was achieved at 34 degree(s) K, where 976 mW of pump power at 806.9 nm produced 166 mW of TEM00 emission. The optical conversion efficiency was 17%. For photon avalanche upconversion pumping at 791.3 nm, 33 mW was produced. The optical conversion efficiency was 3.5%, but the conversion efficiency based on absorbed power is 28%.