Elastomer cholesteric waveguide slab for a transverse elongation

Abstract

ABSTRACT In this work, electromagnetic propagating modes within a planar waveguide featuring a cholesteric elastomer core whose helical axis is oriented perpendicular to the planar boundaries are analysed. The Maxwell equations and the constitutive equation are used to establish a novel configuration, enabling the tuning of mechanical stress through elastic strain in the perpendicular stretching along the helix axis. The derived set of equations is numerically solved, presuming the waveguide to be surrounded by either air or a vacuum medium. The corresponding band structure and the ratio between electric and magnetic modes have been plotted as a function of angular frequency. The amplitudes of the electromagnetic field profiles are also investigated as functions of position. The ratio of Transverse Electric and Transverse Magnetic modes, along with the cut-off frequencies, is also examined as functions of strain. Finally, the mixing of transverse electric and magnetic modes to generate new eigenmodes, as well as the investigation of their propagation conditions within the waveguide, is examined in this study.