0.85 and 1.54 µm emissions of CaF2:Er3+ layers grown by molecular beam epitaxy

Molecular beam epitaxy of CaF 2 monocrystalline layers Er 3+ doped up to a concentration of 50 mol% is demonstrated on CaF 2 substrates. Separated effusion cells containing CaF 2 and ErF 3 have been used. The photoluminescence spectra of these thin layers exhibit emissions from centers which were found to correspond to those already reported for CaF 2 :Er 3+ bulk crystals. The influence of growth temperature and Er concentration on the spectroscopic properties of these layers was investigated. The 1.54 μm emission of interest was shown to behave as aggregate centers, and the integrated luminescence was only quenched for concentrations higher than 35 mol%. The trends observed evidence that molecular beam epitaxy is a powerful technique for growing thin Er-doped fluoride layers