Improved Properties of Stoichiometric LiNbO3 for Electro-Optic Applications
Improved Properties of Stoichiometric LiNbO3 for Electro-Optic Applications
复制标题
用于电光应用的化学计量 LiNbO3 的改进性能
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
H. Hatano
中科院分区：
文献类型：
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作者：
Y. Furukawa;K. Kitamura;Shyunji Takekawa;K. Niwa;H. Hatano
采用配备射频加热自动供粉系统和自动直径控制系统的双坩埚直拉法，成功生长出直径 40 mm、长度 80-100 mm 的高质量化学计量 LiNbO3 单晶。尽管从非同成分熔体生长 3 英寸尺寸的单晶仍然存在一些困难，但我们的结果表明，与同成分 LiNbO3 相比，化学计量 LiNbO3 晶体包含的非化学计量缺陷少得多，对于全息数据存储应用表现出一些有利的特性。双光束耦合实验和数字全息图测试的结果证实了这一点。在数字全息数据存储中，我们已经证明化学计量LiNbO3的光折变灵敏度比同成分LiNbO3高10倍以上。为了解释化学计量LiNbO3的高性能，我们比较了化学计量和同质LiNbO3晶体之间的几个相关参数，例如电光常数、光电导率和光电常数。我们报告说，材料参数在很大程度上取决于非化学计量缺陷的密度，并且这些缺陷的控制对于改善和定制这些性能至关重要。
High quality stoichiometric LiNbO3 single crystals, 40 mm in diameter and 80-100 mm in length, have been successfully grown by the double crucible Czochralski method equipped with automatic powder supply system using radio-frequency heating and automatic diameter control system. Although some difficulties still exist in growing 3 inch size single crystals from offcongruent composition melts, our results demonstrate that stoichiometric LiNbO3 crystals containing much less nonstoichiometric defects than congruent LiNbO3 exhibit some advantageous properties for holographic data storage applications. This was confirmed by the results of two-beam coupling experiment and digital hologram test. In digital holographic data storage, we have demonstrated that stoichiometric LiNbO3 shows more than 10 times larger photorefractive sensitivity than congruent LiNbO3 In order to interpret the high performance of stoichiometric LiNbO3, we compared several relevant parameters such as electro-optic constants, photoconductivity, and photogalvanic constants between stoichiometric and congruent LiNbO3 crystals. We report that material parameters are strongly dependent on the density of nonstoichiometric defects and control of these defects is of key importance in improving and tailoring those properties.