We report cw laser emission of a Pr, Yb-doped ZrF4-BaF2-LaF3-AlF3-NaF
fiber in the red spectral region. Laser emission was achieved on the t
ransition P-3(0) --> F-3(2) (lambda(L) = 635 nm) with a Ti:sapphire pu
mp laser tuned to lambda(p) = 850 nm. A maximum output power of P-out
= 675 mW was obtained at an incident pump power of P-in = 3.37 W. The
output power was increased to P-out = 1020 mW when pumping with P-in =
5.51 W was A photon avalanche process was found to contribute strongl
y to the population of the upper laser level. (C) 1997 Optical Society
of America.