Spectroscopic investigations of Nd 3+-doped alkali chloroborophosphate glasses

Abstract

Optical absorption spectra were studied in wavelength region 400–900 nm for the Nd 3+-doped alkali (R=Li, Na and K) chloroborophosphate glasses at room temperature. The energy level scheme of the 4f 3 electron configuration was deduced from the observed energy level data using a parametrized Hamiltonian ( H F1) model which includes 20 free-ion interaction parameters. Reasonable correlation was obtained between the experimental and calculated energy levels. The Judd–Ofelt model for the intensity analysis of induced electric dipole transitions has been applied to the measured oscillator strengths of the absorption bands to determine the three phenomenological intensity parameters Ω 2, Ω 4 and Ω 6 for each glass. Using these parameters, the total radiative transition rates ( A T), non-radiative relaxation rates ( W NR), branching ratios ( β R), integrated cross-sections for the stimulated emission ( Σ), excited state emission intensities ( f ESE) and excited state absorption intensities ( f ESA) have been theoretically calculated for certain excited Nd 3+ fluorescent levels. From the results obtained, the conclusion is made about the possibility of using these glasses as laser media.