Photodeposition of Ti and application to direct writing of Ti:LiNbO3 waveguides

An ultraviolet laser photodeposition process based on the photolysis of TiCl4 has been developed. The photochemistry of this new metal-halide system has been shown to involve a surface-catalyzed reaction confined to adsorbed molecular layers. By using this process, Ti films have been deposited on LiNbO3 to form, after diffusion, 4-μm-wide single-mode channel waveguides of comparable quality to conventionally fabricated Ti-indiffused guides. The technique introduces new design flexibility into waveguide fabrication, permitting controlled gradations in the diffused index change and the lateral width along the guide.