Knowledge Bank

Cr:$Mg2SiO4$ is a new, promising laser crystal with a wavelength range from 1.1um to 1.3um, but the mechanism of its laser center still remains to be explored. A preliminary study of the electronic structure of the center, in both experiment and theory, has been carried out with systematic data obtained. Experimentally, the normal and polarized transmission spectra, and the LIF spectra of the crystal at room temperature and liquid nitrogen temperature were obtained and analyzed. Both the absorption and fluorescence spectra are the most systematic up to now. It was proved that there should be other types of optical centers besides $Cr31$ in the crystal which is of importance to the laser action. $MS-X\alpha$ calculations were made in the theoretical study. The electronic structure data and energy diagrams of several optical center models which may exist in the crystal were obtained. Comparing the theoretical results with the experimental spectra, the author confirms that the complex $[CrO4]4-$ is the best model of the new optical center which is responsible for the laser emission though $[CrO4]10-$ might also be a reasonnable model.""