The Research And Fabrication Of 2×2 Optical Waveguide Switch

Today optical fiber communication is developing fast. The technology of optical communication has been used in many fields. For example it is used to transmit, rout, distribute and send out all kinds of signals such as sound, video, data, internet, multimedia etc. As key dievices, optical switches are used chiefly in the optical cross connection system in the optical network. Optical swiches can fulfill many functions such as routing, selection to optical wavelength and OXC etc. The theory of machinic optical swich is to shift the optical path by move the optical components or fibers. Its shortcomings are that the switch-time is very long even to milli-seconds, sometimes wobble and repeat will appear. While the theory of waveguide optical switches is to change the refractive index by electrod-optic effect, magnetic-optic effect, acousto-optic effect and thermo-optic effect, which also lead to the change of the optical path. This kind of optical switches have many advantages, such as short switch-time, little cubage, good stability, easy to integrated etc. So it is exigent and important for the institution to reseach better-performance-waveguide-optical switches. In this paper, we analyze the theory of 2×2 LiNbO3 waveguide optical switch deeply. Starting with light transmission theory in the palanr and rectangular medium waveguide, the pattern proper equation of rectangular waveguide is achieved with effegtive refrantive index method, the work principle of 2×2 optical switch is deduced, and the effective refractive index and the coupling length of waveguide is attained. Based on the coupling optical tranmission theory and electric-optical effect, we researched the relationship of luminous power devolution in the coupleing waveguide, single and alternative ?β electrode structure is designed. By formulizing and comparing them, we select the latter as suited electrode structure. At the same time of theory research, the fabrication: photoengraving, sputtering, diffusion scraping and polishing surface, light testing and alignment of electrodes is studied by experiment deeply. Under the existing condition of the lab, a lot of experiments, analyzing and improving are made. Now, the problems in photoengraving, sputtering and diffusion etc. have been solved elementally. Excellent technological parameters are achieved and 2×2 LiNbO3 waveguide optical switch has been fabricated successfully. At the end of this paper, the losses of 2×2 LiNbO3 waveguide type optical switch are analyzed. The testing system is established. The V-grooves used for coupling have been designed.