Gas Phase Proton Exchange Technology

With the coming use of all-optical communication system, the researchers are paying more attention to various optical devices. Most of the optical devices are based on optical waveguids. To improve the optical waveguide, researches are getting more and more vibrant in this area. In this paper, the vapour phase proton-exchange methods (VPPE) are studied . First, the development of LiNbO3 electro-optic modulators and the importance of the research on VPPE are recalled. The advantages of the waveguide produced by the VPPE methods are discussed. Then several kinds of material and the methods that are always used to produce waveguide are listed. The theory of VPPE and the refractive index distribution of the VPPE waveguide are analyzed. The device used in the experiment is designed. Through series of experimentations, the refractive index distribution of the VPPE waveguide is obtained, and compared with PE (proton-exchange) waveguide. Studies show that the VPPE waveguide has good stabilization and it can easily get the single mode waveguide . The waveguide layer of LiNbO3 crystal is analyzed by X-ray diffraction and infrared spectrum. At the end, measuring the transmission loss of slab optical waveguide is dissertated.