Investigation on the mechanical, thermal properties, and refractive index of Er,Pr:GYSGG laser crystal

We investigate the mechanical, thermal properties, and refractive index of (Er0.66Gd1.17)(Pr0.003Y1.167)Sc2Ga3O12 (Er,Pr:GYSGG) crystal with excellent radiation-resistant ability grown by the Czochralski method. The X-ray rocking curve and the optical homogeneity reveal that the Er,Pr:GYSGG crystal possesses high crystalline and optical quality. The crystal density is measured to be 6.03 g cm(-3) by the Archimedes method. The Mohr's hardness is obtained to be 6.42, indicating that the Er,Pr:GYSGG crystal is more conducive to being processed compared with Er:YSGG crystal. The thermal specific, thermal conductivity, and thermal expansion coefficient are determined to be 0.52 J g(-1) K-1, 5.35 W m(-1) K-1, and 8.50 x 10(-6) K-1, respectively. The refractive indices corresponding to a few distinct wavelengths are determined by the minimum deviation angle method, which is used to fit the refractive index curve in the range of 320-3000 nm through the Sellmeier dispersion equation. All these results are of great significance for the further research and laser application of the Er,Pr:GYSGG crystal.