Energy transfer processes in $Li_6(Gd,Y)(BO_3)_3:Ce$ bulk crystals and fibers

The study of the luminescence and energy transfer processes in Li 6(Gd,Y)(BO 3) 3 bulk crystals and fibers by luminescence spectroscopy with time resolution in a wide range of excitation energies have been carried out. There were discovered three types of optically active centers in LGBO:Ce crystals. A new broad luminescence band at 4,4 eV and temperature dependences of intrinsic and impurity luminescence are explained in terms of band electrons and holes recombination processes