Scattering from a perfect electromagnetic conductor (PEMC) sphere using Gaussian vortex beam

The scattering phenomena can be realized in a variety of everyday situations, including the rainbow pattern after a rainstorm, the dispersion of raindrops, information and communication (ICT) systems, radar cross section (RCS) measurement, and remote sensing. Inspired by the electromagnetic scattering features, this study explores the scattering characteristics of orbital angular momentum (OAM) carried by Gaussian vortex beam (GVB) for perfect electromagnetic conductor (PEMC) sphere by utilizing the generalized Lorenz-Mie theory (GLMT). Stemming from the integral localized approximation (ILA) method, the beam-shape coefficients (BSCs) representing the incident GVB are obtained. Vortex beams carry distinct unique optical characteristics as compared to the other beam types as these possess OAM. Computations for the efficiencies (scattering and extinction) for a focused GVB are conducted and discussed to analyze the scattering phenomena of the electromagnetic fields outside the PEMC sphere. To ensure the accuracy of the results, scattering efficiency for Gaussian beam and plane wave is computed and compared using the GLMT for PEMC sphere. The OAM mode index, beam waist radius, and the scalar admittance of GVB are chosen as parameters to investigate their impact on the scattering dynamics (i.e., scattering and extinction efficiency). The numerical results show that OAM mode index, beam waist radius, and PEMC admittance have greater impact on optical efficiencies. Nonetheless, the trend of the scattering efficiency decreases irrespective of the extinction efficiency i.e., increases for OAM mode index.