Study of Propagation Characteristics of Light Beam with Orbital Angular Momentum (OAM) Through a Chiral Medium

The interaction of a Gaussian vortex beam (GVB) with metamaterials during its propagation is of significant interest to the optical community. These GVBs are classified as structured light beams that possess orbital angular momentum (OAM). Understanding the behavior of structured light beams is essential for clarifying fundamental interaction mechanisms with metamaterial structures. So, this work delves into the investigation of the propagation characteristics of a GVB within a chiral material. The analytical expressions for GVB propagating through a chiral medium are obtained by using the extended Huygens–Fresnel diffraction integral formula and the optical ABCD matrix system. In a chiral medium, GVB exhibits a tendency to fragment into a left circularly polarized (LCP) beam and a right circularly polarized (RCP) beam, each following its unique propagation paths. The beam intensity and gradient force are computed and discussed for OAM mode number, beam waist radius, and chirality parameter. This research will be quite helpful for light manipulation, optical sorting, optical radiation force, the radiative transfer process, and optical guiding.