Preparation and Composition Determination of Er~(3+) Doped Near-stoichiometric LiNbO_3 Crystals

Near-stoichiometric Er:LiNbO_3 has many properties superior to congruent one, which has aroused extensive interest. It was prepared by the technique of vapor transport equilibration (VTE) under strict conditions. Its optical properties, including the position of absorption edge, OH - absorption spectra and Raman spectra were measured and studied. The “blue-shift” of the optical absorption edge and the narrower of the Raman peak width, as well as the significant reduction of the OH - absorption band indicate that the Er:LiNbO_3 crystal by the VTE treatment is close to stoichiometric composition.It is caculated that the Li + content is 49.7mol%.