钽酸锂晶体高温富锂扩散工艺的研究

为了采用扩散法制备大厚度近化学计量比钽酸锂(nSLT)晶体,本文从富锂多晶料配比及合成工艺、极化工艺和扩散条件等方面对钽酸锂晶体高温富锂扩散工艺进行了研究,对处理后晶片组分、畴反转电压和光学均匀性进行了表征,研究了扩散条件对晶体组分的影响。结果表明,富锂多晶料锂钽为60/40时较佳,多次使用对所制备晶片组分、畴反转电压和光学质量无明显影响。在研究基础上,制备了系列nSLT晶片,晶片厚度最大为3.2 mm,其组分达到化学计量比且组分均匀,矫顽场约为152 V/mm,晶体光学质量满足实用需求。

Study on High Temperature Lithium-rich Diffusion Process of Lithium Tantalate Crystals

In order to prepare large-thickness near-stoichiometric lithium tantalate(nSLT)crystals by diffusion method,the high temperature lithium-rich diffusion process of lithium tantalate crystals were studied from the aspects of the ratio and synthesis process of Li-rich polycrystalline powders,polarization process and diffusion conditions.The lithium content,poling fields and optical homogeneity of prepared crystals were characterized,and the effect of diffusion conditions on crystal composition was studied.The results show that the repeatable use of lithium-rich polycrystalline material with Li/Ta of 60/40 has no significant effect on the composition,domain inversion voltage and optical quality of the prepared crystal wafers.Based on the research,a series of nSLT wafers were prepared.The maximum thickness of the wafer is 3.2 mm,its composition reaches the stoichiometric ratio and the composition is uniform,the coercive field is about 152 V/mm,and the crystal optical quality meets practical requirements.