Polarization-Independent Black-Phosphorus Polarizer in Visible Regime

We propose black-phosphorous (BP) TE- and TM-pass polarizers whose polarization state can be controlled using strong in-plane anisotropic property of BP. The tunable polarizer is configured as a BP-SiO2metamaterial waveguide to take advantage of the change in refractive index of the whole structure. TE and TM-pass polarizers can be achieved with small footprint (20 μm) and high extinction ratio from 12 to 30 dB for TM-pass polarizer and 17 to 24 dB for TE-pass polarizer. Furthermore, this device exhibits a wide working bandwidth in the visible regime from 500 to 800 nm. Our scheme features simple structure, compact size, and good integrated compatibility, prospecting great potentiality in future optic communications and optical signal processing.