EIA: The Effect of Hydrogen on Optical Damage in Ti DiffusedLiNbO3 Waveguides

这项工作获得了工程启动奖（EIA）的资助。铌酸锂晶体中氢的存在已被发现使ti扩散波导不易受到光折变光学损伤。这个项目旨在了解氢的添加是如何降低损伤的。这项工作将分五个阶段进行：(1)在受控气体环境下的高温退火将用于平衡（氧、锂和水的活性将同时得到控制）；(2)利用红外光谱、拉曼光谱和光学光谱对平衡晶体进行分析；(3)通过书写全息衍射光栅来测量体光折变效应；(4)利用钛的内扩散制备平面波导；(5)测量波导中的光损伤。这些步骤的结果将相互关联，以了解氢缺陷的存在及其影响。更好地了解铌酸锂中的氢将使波导的制造具有更长的寿命和更高的功率传输能力。这一建议描述了将进一步表征铌酸锂的光折变效应的工作。在拟议的研究中获得的理解应该允许制造改进的光学器件。本研究的主要重点将是确定可能存在于铌酸锂中的氢相关缺陷，并评估其对光折变效应的积极或消极影响。鉴定将通过研究在精心控制的环境中平衡的晶体来完成。

This work is funded as an Engineering Initiation Award (EIA). The presence of hydrogen in lithium niobate crystals has been found to make Ti-diffused waveguides less susceptible to photorefractive optical damage. This project is aimed at understanding how the hydrogen additions lower damage. The work will proceed in five stages: (1) Annealing at high temperature in a controlled gas environment will be used for equilibration (oxygen, lithium, and water activities will be controlled simultaneously); (2) FTIR, Raman, and optical spectroscopies will be used to analyze the equilibrated crystals; (3) the bulk photorefractive effect will be measured by writing holographic diffraction gratings; (4) planar waveguides will be made by in-diffusion of titanium; and (5) optical damage in the waveguides will be measured. The results of each of these steps will be correlated to understand what hydrogen defects are present and what their effects are. A better understanding of hydrogen in lithium niobate will allow fabrication of waveguides with longer life and higher power transmission capabilities. This proposal describes work which will further characterize the photorefractive effect in lithium niobate. The understanding obtained in the proposed study should allow the fabrication of improved optical devices. The major thrusts of this study will be to identify hydrogen related defects which are likely to be present in lithium niobate, and to assess their positive or negative effects on the photorefractive effect. The identifications will be made by studying crystals which have been equilibrated in carefully controlled environments.