Growth and fluorescence spectra of LiNbO3 single crystals doped with Eu3+ by Bridgman method

The growth of LiNbO3 single crystal doped with Eu3+ ions by the Bridgman method and the characteristics of temperature-dependent emission spectra were reported. By means of the optimized conditions such as proper raw materials, sealed platinum crucibles, growth rate of 1–3 mm h−1 and convex or plane solid–liquid interface with a temperature gradient around 20–30 °C cm−1, large size crystals containing 0.1 mol% Eu3+ ion with good optical quality were obtained. X-ray diffraction and DTA were used to characterize the crystals. The temperature-dependence emission spectra of lower and upper part of crystals from 77 to 600 K were investigated under the excitation of a 488 nm light. The results show that, for the upper part of crystal, the fluorescence intensity of Eu3+ ions increased with increasing the temperature as a whole. However, for the lower part, it first increased with increasing the temperature, and then decreased obviously with increasing the temperature. The variations of fluorescence intensity for the lower and upper parts of crystals were discussed. The decrease of emission intensity was induced by the temperature-quenching effect.