Abstract We focused on LaBGeO5 (LBGO) single crystal as a novel ferroelectric material for quasi-phase-matching (QPM) devices which are suitable for UV generation. In order to enhance the conversion efficiency of periodically poled LBGO (PP-LBGO), it is required to grow large diameter crystal to obtain PP-LBGO device with long interaction length. However, poly-crystallization were easily happened during LBGO single crystal growth process, and there were several difficulties to increase the diameter. In order to investigate the cause of poly-crystallization, a part of polycrystalline LBGO was characterized by powder X-ray diffractometer. As a result of the measurement, the polycrystalline parts slightly contained La2Ge2O7 phase. By considering the evaporation of B from the melt and optimizing growth conditions, LBGO single crystals with a diameter greater than 30 mm were successfully grown.

中文翻译：

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长相互作用长度 QPM 器件的大直径 LaBGeO5 单晶生长

摘要 我们将 LaBGeO5 (LBGO) 单晶作为一种新型铁电材料，用于适用于产生紫外线的准相位匹配 (QPM) 器件。为了提高周期性极化LBGO（PP-LBGO）的转换效率，需要生长大直径晶体以获得长相互作用长度的PP-LBGO器件。然而，LBGO单晶生长过程中容易发生多晶现象，增加直径存在一些困难。为了探究多晶的成因，用粉末X射线衍射仪对部分多晶LBGO进行了表征。测量的结果是，多晶部分略微含有 La2Ge2O7 相。通过考虑 B 从熔体中的蒸发和优化生长条件，