Oxysulfide optical ceramics doped by Nd3+ for one micron lasing

The spectroscopic characteristics of translucent oxysulfide optical ceramics doped by Nd3+, which can be perspective for 1-μm lasing with high quantum efficiency is considered. Analysis of multiphonon relaxation (MR) rate of the low 4I11/2 laser level in the ceramics is provided using nonlinear theory of MR for multifrequency model of lattice vibration. MR rate dependence for the transitions with equal number of phonons p=4 on the extent of the phonon spectrum and Nd3+ to the nearest ligands distance R0 is established experimentally and analyzed. For the initial 4F3/2 laser level in the Gd2O2S:Nd3+ and La2O2S:Nd3+ ceramic samples an analysis of the energy transfer kinetics is provided. Different stages of energy transfer—direct energy transfer and a stationary migration-controlled stage are observed and analyzed. Dipole–dipole mechanism of energy transfer is established and microparameters of energy transfer and migration are determined.