Multifunctional Metasurfaces Enabled by Multifold Geometric Phase Interference

May 18, 2023·
闵启玄
闵启玄
· 1 min read
Concept of spin-decoupled multifunctional metasurface

🔗 Paper Link

Summary

Geometric phase is frequently used in artificially designed metasurfaces; it is typically used only once in reported works, leading to conjugate responses of two spins. Supercells containing multiple nanoantennas can break this limitation by introducing more degrees of freedom to generate new modulation capabilities.

We provide a method for constructing supercells for geometric phases using triple rotations, each of which achieves a specific modulation function. The physical meaning of each rotation is revealed by stepwise superposition. Based on this idea, spin-selective holography, nanoprinting, and their hybrid displays are demonstrated.

As a typical application, we have designed a metalens that enables spin-selective transmission, allowing for high-quality imaging with only one spin state, which can serve as a plugand-play chiral detection device. Finally, we analyzed how the size of supercells and the phase distribution inside it can affect the higher order diffraction, which may help in designing supercells for different scenarios.

Figure 1. Diagram of the multifold geometric phase interference.

Figure 2. Schematic of the complex field modulation by the multiple geometric phase.

Figure 3. Schematic of spin selective hybrid display/metalens and experimental demenstration of the complex field modulation abilities of our metasurface