Poles and zeros are computed with JCMsuite to generate a basic understanding of how to engineer electromagnetic fields at material interface e.g. metasurfaces. This knowledge can be used to generate full wavefront control of optical components which require spatial phase modulation of incoming beams with a phase from 0 to 2 pi.
R. Colom, et al. Crossing of the Branch Cut: The Topological Origin of a Universal 2?-Phase Retardation in Non-Hermitian Metasurfaces. Laser & Photonics Reviews, 17, 2200976 (2023).