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

By means of the optimum conditions such as proper raw materials, growth rate of l-3 mm/h and convex or plane solid-liquid interface with temperature gradient around 20-30°C/cm, large size crystals containing 0.1 mol% Eu3+ ion with good optical property without micro-defects were obtained by the Bridgman method. X-ray and DTA were used to characterize the crystals. The crystal shows no impurity center under the irradiation of He-Ne laser. The UV/Visible absorption and emission spectra of upper and lower part of crystal were measured. The splitting emission lines were observed. The results showed that the concentration of Eu3+ in LN crystal reduced along the direction of crystal growth, and the Eu3+ ions occupied Li and Nb sites in LiNbO3 crystal.