Heat, fluorescence, and stimulated-emission power densities and fractions in Nd:YAG

We present a comprehensive theory describing the CW balance of heat and fluorescence powers in Nd:YAG and discuss the individual and total heat, fluorescence, and stimulated-emission fractions of the absorbed power, with or without stimulated emission, and as a function of the Nd doping density. /spl chi/ values are presented for both CW and pulsed diode pumping. It is shown that heating due to multiphonon emission and concentration quenching alone cannot account for recent CW measurements of the heat fraction, but that upconversion appears to be a negligible effect.