Incident-angle-insensitive and polarization independent polarization rotator

This paper proposes a method to design an incident-angle-insensitive polarization-independent polarization rotator. This polarization rotator is composed of layers of impedance-matched anisotropic metamaterial (IMAM) with each layer's optical axes gradually rotating an angle. Numerical simulation based on the generalized 4×4 transfer matrix method is applied, and the results reveal that the IMAM rotator is not only polarization-independent but also insensitive to the angle of incidence. A 90° polarization rotation with tiny ellipticity variation is still available at a wide range of incident angles from 0 to 40°, which is further confirmed with a microwave bi-split-ring resonator (bi-SRR) rotator. This may be valuable for the design of optoelectronic and microwave devices.