Interferenceless Polarization Splitting through Nanoscale van der Waals Heterostructures

The ability to control the polarization of light at the extreme nanoscale has long been a major scientific and technological goal for photonics. Here we predict the phenomenon of polarization splitting through van der Waals heterostructures of nanoscale thickness, such as graphene-hexagonal boron nitride (hBN) heterostructures, at infrared frequencies. The underlying mechanism is that the designed heterostructures possess an effective relative permittivity with its in-plane (out-of-plane) component being unity (zero); such heterostructures are transparent to the transverse-electric (TE) waves while opaque to the transverse-magnetic (TM) waves, without resorting to the interference effect. Moreover, the predicted phenomenon is insensitive to incident angles. Our work thus indicates that van der Waals heterostructures are a promising nanoscale platform for the manipulation of light, such as the design of polarization beam nano-splitters and epsilon-near-zero materials, and the exploration of superscattering for TM waves while zero scattering for TE waves from deep-subwavelength nanostructures.