Efficient calculation of far-field patterns of waveguide discontinuities using perfectly matched layers

A new efficient method is outlined for calculating the far-field pattern of waveguide discontinuities. An open configuration is turned into a closed configuration using perfectly matched layers. Using a mode-matching scheme on the resulting configuration, the total field on the discontinuity can be determined. The far-field is calculated by taking the Fourier transform of this field and multiplying it by the Huygens obliquity factor. Results are presented for a GaAs-AlGaAs laser facet and a truncated grounded dielectric slab