Spectral Investigations on Ho3+ Doped Mixed Alkali Chloroborate Glasses

Abstract

The optical absorption and emission spectra of two different Ho3+ doped mixed alkali chloroborate glasses have been studied in the ultraviolet-visible near-infrared regions. Various spectroscopic parameters like Racah (E1, E2, and E3), spin orbit (ξ4f), and configuration interaction (α) parameters have been calculated. From the measured spectral intensities of the various absorption bands of Ho3+ ion, the Judd–Ofelt intensity parameters (Ω2, Ω4, and Ω6) have been evaluated and covalency was studied as a function of x in the glass matrices. Using these parameters, radiative transition probabilities, radiative lifetimes, branching ratios, and integrated absorption cross-sections have been calculated and reported for certain excited states of Ho3+ ion. From the emission spectra, stimulated emission cross-sections are determined for the emission transitions, 5F4, 5S2 → 5I8, and 5F5 → 5I8 in these two mixed alkali chloroborate glasses. An attempt has been made to throw some light on the environment of Ho3+ ions in these glass systems by studying the variation in various spectroscopic parameters.