We report on the experimental measurement; of the saturated gain of Yb3+:Sr
-5(PO4)(3)F at the 1047-nm laser line as a function of pump fluence and pro
be energy. The emission line was accurately modeled as a single homogeneous
extraction, yielding values of 6.2 x 10(-20) cm(2) for the emission. cross
section and 3.3 J/cm(2) for the saturation fluence. (C) 2000 Optical Socie
ty of America.