Numerical analysis of miter bend with spiral phase mirror

Abstract

To excite optical vortices using high-power millimeter waves, we use a miter bend with a spiral phase mirror. Through numerical simulations, we demonstrate that vortex beams can be successfully excited by employing a spiral phase mirror that appropriately accounts for the phase difference between the input and output modes. The simulations also reveal the generation of higher-order modes caused by diffraction inherent to the miter bend structure and unintended reflections arising from the singularity at the optical axis of the spiral phase mirror. Additionally, we propose a method to estimate the topological charge, which corresponds to the vorticity, from real-valued data. The simulation results confirm that vortex beams are successfully excited as the dominant mode.journal articl