VUV spectroscopy of a new fluoride system NaF-(Er, Y)F3

Emission and excitation spectra as well as luminescence decay kinetics of a new complex fluoride system Na-0.4(Y1-xErx)(0.6)F-2.2 (x = 0.01, 0.1, 1) have been studied in the vacuum ultraviolet (VUV) spectral range. It has been shown that these crystals have intense VUV luminescence due to the interconfiguration 5d-4f transitions in Er3+ ion. The spin-allowed 5d-4f luminescence of Er3+ in this system is very weak, i.e., in these crystals there exists an efficient non-radiative relaxation from higher-lying 5d states of Er3+ to the lowest 5d level responsible for spin-forbidden luminescence. This makes the studied new fluoride system a promising active medium for the production of VUV solid state laser with optical pumping. Due to rather large bandwidth of Er3+ 5d-4f luminescence in this system there is a possibility for the construction of tuneable VUV laser. (C) 2001 Elsevier Science B.V. All rights reserved.