Optical transitions of erbium-doped sodium lanthanum gallate glasses

Abstract

Erbium ion doped sodium lanthanum gallate glasses (Na2O-La2O3-Ga2O3 or NLG) which are suitable for use in optical waveguide devices has been fabricated and characterized. The density, the refractive indexes, the absorption and luminescence spectra along with the luminescence decay time were measured. Using the experimental oscillator strengths, the Judd-Ofelt intensity parameters Ωt were determined, and some important radiative properties were calculated. The emission peak of the 4I13/2 → 4I15/2 transition is at the 1.53-μm wavelength. The full-width at half-maximum (FWHM) bandwidth is 38 nm, which is larger than that of Er3+-doped Ge/P silicate glasses (24.7nm), and comparable to that of Er3+-doped Al/P silicate glasses (43.3nm). The lifetime of the 4I13/2 level is 7.03ms and the quantum efficiency is ∼100%. The results show that the NLG glass is an excellent host material for applications in fiber amplifiers and waveguide lasers.