Polarization Raytracing - Simulation of real-world polarization devices in ASAP

This technical publication describes polarization raytracing features in the Advanced Systems Analysis Program (ASAP®) from Breault Research Organization (BRO). Analysis of polarization has been a part of ASAP for much of its history. With the advent of ASAP 2008 and continuing with ASAP 2009, significant new features have enhanced this capability.

New classes of polarization elements have been added that improve the simulation of a range of real-world devices. Source polarization may be controlled using an explicitly defined reference ray, and randomization of source polarization makes it possible to model effects that idealized sources cannot produce. Ray distribution files can now include polarization data, and these files can be loaded to re-create a polarization field from previous ray trace results. Ray polarization data may be tracked in Jones vector mode or in Stokes vector mode, with the latter enabling modeling of partial polarization effects. Device-definition commands are now available for General Axial Medium (GUM) and Liquid Crystal Cell (LCC). GUM is based on the behavior of uniaxial birefringent materials under a small-birefringence approximation. LCC is a model for typical liquid crystal materials with spatially varying uniaxial birefringence.

Analysis features include output of polarization data in Jones or Stokes vector form, and a Poincaré Sphere Visualization Tool to show polarization state data and to allow exploration of the relationship among polarization, flux, position, and direction of rays.