Exhibition of circular Bragg phenomenon by hyperbolic, dielectric, structurally chiral materials

The relative permittivity dyadic of a dielectric structurally chiral material (SCM) varies helicoidally along a fixed direction; in consequence, the SCM exhibits the circular Bragg phenomenon, which is the circular-polarization-selective reflection of light. The introduction of hyperbolicity in an SCM—by making either one or two but not all three eigenvalues of the relative permittivity dyadic acquire negative real parts—does not eliminate the circular Bragg phenomenon, but significantly alters the regime for its exhibition. Physical vapor deposition techniques appear to be suitable to fabricate hyperbolic SCMs.