Transient population dynamics in flashlamp pumped sensitized erbium glass lasers

Erbium population dynamics in ytterbium sensitized phosphate glass is studied by measuring transient changes in laser probe transmission during flashlamp pumping. The influence of energy loss channels such as excitation cumulation and nonlinear fluorescence quenching on the flashlamp pumping efficiency is observed to be relatively small. The decrease of the pumping efficiency at high input energies can be attributed mostly to the blue shift in the flashlamp output radiation spectrum.