Lithium Niobate For Integrated Optical Spectrum Analyzer Line Acoustic Waveguide,

In X-cut LiNbO3, proton exchange process results in enhanced confinement of both optical field and acoustic field. Furthermore, the guide mode in X-cut proton exchange LiNbO3 waveguide is TE mode, otherwise TM mode is the leaky mode. Thus, collinear acousto-optic interaction in the said waveguide will result in the transformation of guide mode to leaky mode. Based on the foregoing phenomenon, the scheme of X-cut proton exchanged LiNbO3 serving as not only optic but acousto channel waveguide is provided in this paper. Using the collinear AO interaction in the said waveguide,spectrum analysis can be achieved。This paper addresses acousto-optic properties of proton exchange LiNbO3 waveguide to be a basis for decision of proton exchange conditions. Based on output properties and delta function model of IDT (inter digital transducer), structure parameters of IDT are designed.To find out the relationship between acousto-optic properties of waveguides and conditions of proton exchange process, many times of proton exchange process, using benzoic acid as proton resource, are accomplished. Furthermore, the paper develops some practicable measures to modify the craft process. Finally, a planar proton exchanged waveguide on LiNbO3 is completed.