New formulations of the matrix beam propagation method: applicationto rib waveguides

A technique for the spectral analysis of strongly guided optical waveguiding media based on a variant of the recently introduced matrix beam propagation algorithm is discussed. In particular, it is shown that the lowest order modes of rib waveguides can be generated with a simple computer program using this method. The results are also obtained using a standard finite-element procedure. The relative efficiency of the two methods is considered. The propagating electric field and differential losses in a Y junction fabricated from rib waveguides are also evaluated