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

We propose a design of bilayer metasurfaces, imposing arbitrary and independent phase profiles on arbitrarily polarized beams at lambda (1) = 505 nm and circularly polarized beams at lambda (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 lambda (1), while polarization-dependent deflector or dual-foci metalens are designed at lambda (2). We demonstrate a simple yet effective approach interconnecting phase distributions and flexible polarization responses, which holds great promise in information multiplexing and security.

Automated summary

We propose a design of bilayer metasurfaces for arbitrary and independent phase modulation of arbitrarily polarized beams at lambda (1) = 505 nm and circularly polarized beams at lambda (2) = 633 nm. The method involves cascading two layers functioning as convertible waveplates and full-wave plates. We investigate the performances of asymmetric deflectors and multi-foci metalenses, achieving polarization-independent deflector or single-focus metalens at lambda (1) and polarization-dependent deflector or dual-foci metalens at lambda (2). The proposed approach shows promise in information multiplexing and security.