Measurements of heating and energy storage in flashlamp-pumped Nd:YAG and Nd-doped phosphate laser glasses

We have experimentally measured the energy stored and the heat generated in flashlamp-pumped Nd:YAG and six different commercially available Nd-doped phosphate glasses. We find that the normalized heating parameter
X
, defined as the heat deposited per unit stored energy, is 1.5-2 times the value expected from the known spectroscopy of the Nd ions in these hosts and the emission spectrum of Xenon flashlamps. We discuss the heat sources in Nd-doped glasses. Using a theoretical model, we calculate the influence of Nd concentration, flashlamp pulse length, and current density on
X
, and we point out the effects of
X
on practical laser designs.