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

Abstract Emission and excitation spectra as well as luminescence decay kinetics of a new complex fluoride system Na 0.4 (Y 1− x Er x ) 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 Er 3+ ion. The spin-allowed 5d–4f luminescence of Er 3+ in this system is very weak, i.e., in these crystals there exists an efficient non-radiative relaxation from higher-lying 5d states of Er 3+ 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 Er 3+ 5d–4f luminescence in this system there is a possibility for the construction of tuneable VUV laser.