# Quasioptical modeling of wave beams with and without mode conversion: III. Numerical simulations of mode-converting beams

## TL;DR

This paper presents numerical simulations of mode-converting electromagnetic beams using a quasioptical modeling algorithm, demonstrating the PARADE code's ability to accurately simulate beam splitting and mode conversion phenomena.

## Contribution

It introduces the first quasioptical simulations of mode-converting beams and validates the PARADE code against full-wave and ray-tracing simulations.

## Key findings

- PARADE accurately models mode conversion and beam splitting.
- Simulation results agree with full-wave and ray-tracing methods.
- The approach advances quasioptical modeling capabilities.

## Abstract

This work continues a series of papers where we propose an algorithm for quasioptical modeling of electromagnetic beams with and without mode conversion. The general theory was reported in the first paper of this series, where a parabolic partial differential equation was derived for the field envelope that may contain one or multiple modes with close group velocities. In the second paper, we presented a corresponding code PARADE (PAraxial RAy DEscription) and its test applications to single-mode beams. Here, we report quasioptical simulations of mode-converting beams for the first time. We also demonstrate that PARADE can model splitting of two-mode beams. The numerical results produced by PARADE show good agreement with those of one-dimensional full-wave simulations and also with conventional ray tracing (to the extent that one-dimensional and ray-tracing simulations are applicable).