A fast physical optics method for the analysis of beam waveguides
A fast physical optics (PO) method is presented which in two steps calculates the scattered field of an optical component in a beam waveguide (BWG). The first step involves a calculation of a set of equivalent currents on an auxiliary plane and the second step a field calculation from this current set.
The present work has been motivated by the major difficulties associated with accurate analysis of a complex BWG system at THz frequencies. One major difficulty is the use of components in the BWG that are large in wavelength. These components will make field calculation through the BWG using standard PO methods computationally time consuming. An immediate way to overcome this problem could be to apply ray-tracing techniques. However, for a complex BWG with many components, ray tracing is often inaccurate or impractical. Another way to overcome the problem could be to use Gauss-Laguerre beam expansion techniques. In many configurations  these techniques do provide fast and efficient ways to trace the beam.
Publication: 25th Antenna Technology Workshop Digest
Place: ESTEC, Noordwijk, The Netherlands, 18-20 September 2002