Excited-state absorption at 1.3 μm in Nd 3+-doped fluoride and sulfide glasses

Abstract

Excited-state absorption (ESA) and emission spectra are recorded from the 4F 3/2 level of Nd 3+ ions in Zr–Ba–La–Al–Na (ZBLAN) and Ba–In–Ga (BIG) fluoride glasses and in Ge–Ga–S–Cs–Cl (GGSC) chlorosulfide glass. The respective contributions of stimulated emission (SE) and ESA are determined in the 1.3 μm region, a spectral domain that corresponds to the second telecommunication window. The pump–probe technique utilized in this study predicts the gain profile as a function wavelength in optical fibers. Gain is expected at wavelengths greater than 1.31 μm with ZBLAN and BIG, and 1.35 μm with GGSC. It is shown that the relative intensities of SE and ESA processes can be evaluated with consistency by Judd–Ofelt calculations.