Controlling waveguide modes using PT transformation media

Abstract

We study rectangular waveguide modes loaded with parity-time PT transformation media derived by complex transformation optics CTO approach. PT transformation media are obtained through mirror symmetric complex coordinate transformations resulting in a balanced loss/gain media. It is shown that waveguide modes can be controlled by simply changing the imaginary part of the complex coordinate transformation while not affecting any other characteristic of the waveguide. The field distribution inside the waveguide can either be stretched towards the sides or squeezed at the center of the waveguide by employing different loading configurations.