Multiphonon relaxation of rare-earth ions in beryllium-fluoride glass

Abstract

Relaxation of excited electronic states of rare-earth ions by multiphonon emission was investigated in a beryllium-fluoride glass. Decay rates were measured from the transient fluorescence following pulsed laser excitation of selected states. The multiphonon emission rates exhibit an approximately exponential dependence on the energy gap to the next-lower state and are in general agreement with the phenomenological treatment of multiphonon processes.