DESIGN OF SINGLE MODE ANNEALED PROTON EXCHANGED LiNbO_3 WAVEGUIDES BY EFFECTIVE-INDEX BASED MATRIX METHOD

摘要

Effective-index based matrix method is used to analyse annealed proton exchanged (APE) LiNbO_3 waveguides. The variation of refractive index with the fabrication parameters, such as, exchange time, annealing time, waveguide width, and transmitting wavelength is studies. The computed surface refractive index changes of the waveguides are compared with the published experimental results. The 2D transverse refractive index profde of the APE lithium niobate waveguide is transformed to the laterial 1D effective index profile by WKB method, which is then discretised using a partitioning scheme. The matrix method is then applied to obtain the propagation constants of the guided modes. Variation of propagation constant with the fabrication parameters of APE waveguide is studied and the single mode APE lithim niobate channel waveguides are designed.