Spectral, luminescence, and lasing properties of Nd3+ ions in systems utilizing GaCl3–SOCl2 and AlCl3–SOCl2 inorganic liquid media

An investigation is made of the absorption and luminescence spectra and of the decay kinetics of the ⁴F_3/2 metastable level of the Nd³⁺ ion in the GaCl₃–SOCl₂ concentration series and in an AlCl₃–SOCl₂:Nd³⁺ sample at temperatures of 300, 77, and 4.2°K. It is established that in GaCl₃–SOCl₂ and AlCl₃–SOCl₂ systems the neodymium ions form several types of activator centers corresponding to different structures of the nearest coordination sphere of the neodymium ion, which is a complexing agent. The phenomenological Judd-Ofelt model is used to calculate the most important characteristics of the radiative transitions of the Nd³⁺ ion in a GaCl₃–SOCl₂–NdCl₃ system. Lasing at 1.058μ with a threshold of 0.5 J/cm was obtained in a GaCl₃–SOCl₂ system.