Optical studies of chromium doped zinc oxy fluoro borate glasses – A possible disordered material for tunable LASERS

Abstract Melt-quenching technique adapted to prepare the (10-x)ZnO-30ZnF2-60B2O3: xCr2O3 (x: 0.2, 0.4, 0.6, 0.8, 1.0) (mol %) glasses. Various physical parameters are estimated with the help of experimental densities and refractive index. Optical absorption studies reveal that the chromium ions exist in Cr3+ state at very low concentrations, whereas the concentration increases chromium ions occupies both Cr3+ and Cr6+ state. Crystal field (Dq) and Racah parameters (B and C) are calculated by the crystal field relations. Direct and Indirect optical band gaps are calculated from the absorption edges. Finally, by means of optical studies, the behaviors of Cr ions in present glasses are discussed.