Blue, green and red fluorescence and energy transfer of Eu 3+ in fluoride glasses

Abstract

Solid state blue and green light sources are desirable for high density optical storage, color displays, optoelectronics, and medical diagnostics. In addition to the well-known red emission of Eu 3+, strong green, blue, and ultraviolet emissions have been observed in Eu 3+ doped ZBLA (57ZrF 4·36BaF 2·4LaF 3·3AlF 3) and PIGLZ (43PbF 2·17InF 3·17GaF 3·4LaF 3·19ZnF 2) fluoride glasses. The intense concentration dependence of these emissions was examined with fluorescence and excitation spectroscopy and found to be caused by nonradiative dipole-quadrupole and dipole-dipole energy transfer between excited and ground state Eu 3+ ions. Judd-Ofelt analysis, transfer efficiency, and phonon side band measurements were used to model the fluorescence, energy transfer, and gain cross section for Eu 3+ in a ZBLA host.