Zn,Cr∶LiNbO3单晶的坩埚下降法生长及其荧光光谱

通过选择合适的化学原料（Li2O∶48.6mol%, Nb2O5∶51.4mol%）、控制生长速度（<3 mm/h）及固液界面的温度梯度（20~40℃/cm）与温场，用坩埚下降法成功地生长出了Zn、Cr双掺杂初始浓度分别为3 mol%、0.1 mol%,以及6 mol%、0.1 mol%的大尺寸铌酸锂晶体.生长的晶体无宏观缺陷,在He-Ne激光的照射下，无散射中心.测定了晶体的宽带荧光光谱（700~1200nm）及R带（710~740nm）的精细变温光谱.这些R带的光谱线由Cr离子所取代的Li(Cr3+Li)与Nb(Cr3+Nb)的发光中心以及声子辅助吸收所致.

Growth of LiNbO3 Single Crystals Co-doped Fe and Zn by Bridgman Method and Their Emission Spectra

Through the proper conditions such as feed materials with proper composition (Li_2O 48.6 mol%, Nb_2O_5 51.4 mol%), growth rate of less than 3 mm/h, a temperature gradient of 20~40℃/cm across the solid-liquid interface and suitable gradient field of the whole furnace,LiNbO_3 crystals co-doped with Cr 3+ ions in 0.1 mol% and Zn in 3 and 6 mol% can grow,respectively, by Bridgman method.The crystals without micro-defects are obtained, and there is no impurity center under the irradiation of He-Ne laser. The emission spectra between 700~1200 nm and the temperature-dependence emission spectra of R lines at 710~740 nm were measured. The observed R lines were attributed to the different Cr 3+ ion sites (Cr 3+_ Li and Cr 3+_ Nb) and the hot phonon-assistant absorption.