Numerical analysis of integrated acoustooptic tunable filters with weighted coupling

A numerical approach is newly formulated for design and modeling of integrated acoustooptic tunable filters (AOTF's) with weighted coupling. First, acoustical field profiles in the substrate region and on the substrate surface are separately calculated with the finite element method (FEM) and the beam propagation method (BPM), respectively. These two-dimensional (2-D) profiles are used for constructing three-dimensional (3-D) strain and electric field profiles. Then, from the strains and electric fields the refractive index changes are derived. Finally, by analyzing modified optical waveguides with acoustooptic (AO) and electrooptic (EO) induced changes in refractive indices using again BPM, optical filter characteristics of AOTF's can be evaluated.

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