Spectroscopic and lasing characteristics of sapphire crystals containing color centers in the 1.0-μm range

An investigation was made of the kinetics of changes in the absorption spectra of sapphire crystals containing radiation color centers at various annealing temperatures. Studies were made of the excitation and luminescence spectra, the quantum efficiency, and also the feasibility of stimulated emission from color centers in the 1.0-μm range. It was established experimentally that the conversion efficiency of the radiation depended on the integrated neutron flux and the temperature of the subsequent heat treatment. It was found that, in a laser utilizing sapphire containing color centers, the emission wavelength could be tuned continuously between 0.75 and 1.1 μm by using a single pump source. The conditions for photostability of the color centers were determined.