The semivectorial beam propagation method

Details of an efficient semivectorial beam propagation method are presented. The propagation is determined by solving the finite-difference equation in alternating directions. Unlike the traditional split-operator beam propagation method, in the semivectorial method the index term is not separated from the spatial differentiations. Since boundary conditions at dielectric interfaces can be satisfied by two orthogonal polarizations individually, the method is semivectorial. The performance can be enhanced by using a nonuniform grid. By modifying the routine, it can also be applied to periodic structures. Numerical results for rib waveguides are presented.<
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