Suppression of Li2O Out-Diffusion from Ti-Diffused LiNbO3 Optical Waveguides.

摘要

Light guides fabricated by Ti diffusion into y-cut LiNbO3 are attractive because of the possibility of using the largest electro-optic coefficient (r sub 33). However, the accompanying Li2O out-diffusion gives rise to unwanted guided modes which are a problem in electro-optic modulators. To overcome this problem it is necessary to reintroduce Li back into the crystal by some means. This report is on a simple but effective process (using Li2O) to suppress Li2O out-diffusion and realize single-mode Ti-diffused LiNbO3 light guides in a y-cut orientation. A natural extension of the above process to Ti-diffused LiTaO3 light-guiding structure should be possible.