Room-temperature upconversion laser operation has been demonstrated at 456, 482, 512, 649, and 799 nm in the ytterbium-sensitized thulium system in BaY2F8. With 960-nm titanium–sapphire laser pumping, cw operation of the 649- and the 799-nm upconversion laser transitions is observed. We believe that this is the first observation of laser emission on the 799-nm transition from 1G4 and the 512-nm transition from 1D2 in a bulk-crystal sample. At reduced temperatures cw or quasi-cw laser operation is obtained on the 456-, the 482-, and the 512-nm transitions. Room-temperature diode-laser pumping has been demonstrated for the 456-, the 512-, and the 649-nm transitions.
© 1994 Optical Society of America
R. J. Thrash and L. F. Johnson, "Upconversion laser emission from Yb3+-sensitized Tm3+ in BaY2F8," J. Opt. Soc. Am. B 11, 881-885 (1994)