Dual-band bilayer metasurfaces enabling platforms for independent polarization sensitive/insensitive modulations

Abstract

Abstract We propose a design of bilayer metasurfaces, imposing arbitrary and independent phase profiles on arbitrarily polarized beams at λ 1 = 505 nm and circularly polarized beams at λ 2 = 633 nm. The method cascades two layers that separately function as convertible waveplates and full-wave plates for modulation of polarization and phase. We investigate the performances of the asymmetric deflector and multi-foci metalenses. Specifically, polarization-independent deflector or single-focus metalens can be achieved at λ 1, while polarization-dependent deflector or dual-foci metalens are designed at λ 2. We demonstrate a simple yet effective approach interconnecting phase distributions and flexible polarization responses, which holds great promise in information multiplexing and security.