大尺寸近化学计量比铌酸锂晶体的制备

Preparation of Large Size near Stoichiometric Lithium Niobate Crystals

研究了扩散法制备近化学计量比铌酸锂晶体的工艺,从原料配比、合成方式、晶片放置方式和扩散工艺等方面进行了工艺优化。对不同厚度和切割方向的铌酸锂晶体进行扩散处理,对三英寸Z-cut铌酸锂晶体进行了批量扩散试验,并对扩散后的晶体进行了组分和均匀性测试。结果表明,厚度为3.1 mm的Z-cut晶体组分达到近化学计量比,光学质量达到实用化要求,而XYZ=5.1 mm×5.1 mm×21.0 mm的晶体光学质量较差,同时厚度达1.8mm的Z-cut三英寸近化学计量比铌酸锂晶片可实现批量制备。

Diffusion method for preparation of near stoichiometric lithium niobate crystals was studied,and improved by the technology conditions including lithium content,synthesis method of Li-rich power,wafers placement and diffusion process. Lithium niobate crystals with different sizes and different orientations were diffusion treated,and Z-cut three-inches wafers were treated in batch,then the lithium content and optical homogeneity of treated crystals were checked. The expertments show that lithium content of Z-cut cystal with 3. 1 mm thickness reaches near stoichiometry value,its optical quality meets the practical usage demands,but the optical quality of Z-cut crystal with size of XYZ = 5. 1 mm × 5. 1 mm× 21. 0 mm is poor,meanwhile,Z-cut three-inches wafers with 1. 8 mm thickness can be prepared by diffusion method in batch.