Crystal growth and optimization of Pr:CaGdAlO4 by the flux-Czochralski method

Abstract

Pr:CaGdAlO₄ (Pr:CGA) crystals have been grown and investigated for the first time. A Na⁺ flux was designed to improve the crystal quality in the Czochralski growth process. The effect of the addition of the Na⁺ flux on crystal quality has been investigated, and its beneficial impact on the crystallinity, optical homogeneity and thermal properties of the grown crystals has been demonstrated. The optical spectra of Pr:CGA have been measured in order to assess its potential for photonics applications. The intensities of the absorption transitions have been analyzed by means of the Judd–Ofelt approach and the intensity parameters, the branching ratios and the radiative lifetimes of the emitting states have been evaluated. These have been compared with the experimental values obtained from pulsed light measurements. All the properties indicate that the Pr:CGA crystal has great prospects in the applications of visible lasers.