Silver halide lasers and amplifiers: Nd ion diffusion in AgBr crystals

The luminescence of silver bromide crystals doped with rare earth ions (Nd³⁺) was investigated in the visible and near infrared spectral ranges. The emission, excitation, and absorption spectra, as well as the kinetic parameters, were measured over a broad temperature range. Crystal doping was produced by growing in the melt and by a diffusion method. A novel method for measuring the diffusion profile of rare earth ions in AgBr crystals, based on the luminescence distribution of the dopant, was proposed. The luminescence parameters of AgBr:Nd crystals doped by the diffusion method were compared with these for crystals doped by adding Nd³⁺ to the melt. The spectroscopy parameters of Pr³⁺ and Er³⁺ ions in AgBr crystals doped in the melt were also investigated. The Judd-Ofelt analysis was applied to the rare-earth doped crystals, and transition rates, branching ratios, and quantum efficiencies were calculated. Good agreement between theory and experiment was obtained.