On the kinetics of nonradiative energy transfer in Yb – Er phosphate glasses excited by a diode laser

The luminescence of a Yb – Er phosphate glass excited by a diode laser is studied as a function of the density of energy absorbed by a sample and the pump radiation intensity. An abrupt change in the depopulation rate of the Yb³⁺(²F_5/2) level was observed after switching off the pump laser. This effect is explained qualitatively based on the kinetics of nonradiative energy transfer in glasses and crystals.