Full-channel wavefront manipulation of surface waves with chirality-assisted geometric-phase metasurface

TL;DR

This paper introduces a chirality-assisted geometric-phase metasurface that enables independent, multi-channel surface wave manipulation, significantly advancing on-chip communication and photonic system capabilities.

Contribution

It presents a novel chirality-assisted phase control mechanism that decouples co- and cross-polarized channels, allowing four-channel surface wavefront shaping.

Findings

Demonstrated four-channel SW meta-deflector and metadevice in microwave range

Achieved simultaneous focusing, Bessel beam generation, and beam deflection

Validated effectiveness through numerical and experimental results

Abstract

Owing to their localized field enhancement and subwavelength resolution, surface waves (SWs) offer broad application potential in communications, sensing, and photonics via on-chip wavefront manipulation. This makes multi-channel SW wavefront manipulation highly desirable. However, conventional metasurfaces for SW wavefront shaping, relying on geometric and propagation phase mechanisms, typically exhibit similar functionalities for co- or cross-polarized output channels under different circularly polarized (CP) incidences, thereby limiting the development of high-capacity on-chip integrated devices. Here, by introducing the chirality-assisted phase as an additional phase control mechanism, we effectively decouple both co- and cross-polarized output channels, enabling independent SW wavefront shaping in four distinct channels. We numerically and experimentally demonstrate two metasurfaces in the microwave range: a four-channel SW meta-deflector and a four-channel SW metadevice that simultaneously produces a focused SW beam, a SW Bessel beam, and two deflected SW beams in different directions. Therefore, chirality-assisted geometric-phase metasurfaces provide a versatile platform for multi-channel SW wavefront engineering, offering significant potential for high-capacity on-chip communication and integrated photonic systems.