Abstract
This paper presents the electromagnetic field expressions for 3D cassegrain system embedded in a bi-isotropic chiral medium. Mathematical formulation of Maslov is used to find the field expressions in the focal region. Effect of chirality (both the week and strong) on focal region fields is analyzed. It is seen that when the chirality effect is weak (i.e., kappa < 1), chiral medium will support positive phase velocity (PPV) for both the left circularly polarized (LCP) and the right circularly polarized (RCP) modes. However for strong chiral medium (i.e., kappa > 1), one mode travels with PPV and the other mode travels with negative phase velocity (NPV). The line plots are given to show the behavior of fields in the focal plane of 3D cassegrain system by changing the chirality parameter (kappa).