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.