Oxysulfide optical ceramics doped by Nd~(3+) for one micron lasing

摘要

The spectroscopic characteristics of translucent oxysulfide optical ceramics doped by Nd~(3+), which can be perspective for 1-μm lasing with high quantum efficiency is considered. Analysis of multiphonon relaxation (MR) rate of the low ~4I_(11/2) 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 Nd~(3+) to the nearest ligands distance R_0 is established experimentally and analyzed. For the initial ~4F_(3/2) laser level in the Gd_2O_2S:Nd~(3+) and La_2O_2S:Nd~(3+) 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.