Design of reflectionless non-magnetic homogeneous polarization splitters with minimum anisotropy based on transformation electromagnetics

Abstract

Design and realization of polarization splitting devices present several common challenges. Unwanted reflections from boundaries of the device and material anisotropy are among the major ones. We present a transformation electromagnetics-based method to design non-magnetic homogeneous polarization splitters that are reflectionless and have minimum anisotropy. This is accomplished by utilizing an area-preserving linear transformation with proper reflectionless conditions at the input and the output boundaries of the device. The condition of minimum anisotropy is determined analytically. This is done for the first time, to the best of our knowledge. The proposed devices enhance the performance of the optical systems by providing ideal transmission. The realizability of the device is also improved by minimization of the anisotropy. Several polarization splitters are designed which create an arbitrary deflection angle or lateral shift between TE and TM polarizations. In addition, the effective medium theory is employed to realize one of the designs by using equivalent dielectric layers. In order to verify the proposed methodology, the designed devices are simulated by the commercial software COMSOL Multiphysics.