The effective frequency in multiphonon processes: Differences for energy transfers or side-bands and non-radiative decay

Abstract

We have found that the exponential parameters for multiphonon side-band excitation for Er 3+:ZBLAN and Er 3+:silica glasses are respectively 9.3 × 10 −3 and 8.3 × 10 −3cm for Stokes and 14 × 10 −3 and 13.4 × 10 −3 cm for anti-Stokes excitation. These values are much higher than the ones usually reported for non-radiative decay: 5.2 × 10 −3 cm for ZBLAN and 3.8 × 10 −3 cm for silica glass. Such behaviour is linked to a constant value of 1.2% for the multiphonon generation quantum efficiency.