Abstract

Diode laser pumped, room temperature upconversion lasers are one possible route to ail solid-state visible wavelength laser devices. Room temperature, upconversion laser operation has been obtained by using barium yttrium fluoride doped with either thulium or erbium ions, and sensitized with ytterbium. The 960 nm output from a titanium sapphire laser or diode laser serves as the pump source. Excitation is accomplished by means of energy transfer from ytterbium to the active ion. Successive transfers of energy from ytterbium to the active ion, as well as cross-relaxation processes among the active ions, distribute the energy to the various excited states responsible for the laser emission. Laser operation has been obtained at wavelengths in the red, green, and blue regions of the visible spectrum. Several of these transitions are capable of cw operation. A discussion of the pumping processes and recent results will be presented.

© 1992 Optical Society of America