Singularities of ray and caustic structures of electromagnetic waves in metamaterials

Abstract

Ray and caustic structures formed during propagation of electromagnetic waves from a point source of electromagnetic radiation in a layer of a metamaterial with a negative refractive index are studied. Propagation of waves in a homogeneous layer bounded by curvilinear surfaces with circular and parabolic shapes, i.e., in lenses of metamaterials, is analyzed. Propagation of waves in an inhomogeneous layer is considered in the cases of longitudinal and transverse variations in the refractive index. Caustic structures corresponding to wave catastrophes of caspoid and ombilic series are found. The possibility of backward waveguide propagation in a metamaterial is shown