Efficient analysis of plasmonic discontinuities

Blocked Schur finite-element bidirectional beam propagation method (BS-FE-BiBPM) is introduced for high-index contrast plasmonic waveguides with multiple-longitudinal discontinuities. The square root of the characteristic matrix appearing at the discontinuity section is accurately computed using the newly Blocked Schur algorithm which could save, by serial implementation only, about 60% of the execution time comparing with Schur algorithm. The suggested BS-FE-BiBPM overcomes the stability and accuracy problems of the conventional BiBPMs based on the commonly used Padé approximation in dealing with plasmonic devices thanks to a physically treatment of evanescent and surface waves.