Guided-Wave-Excited Metasurface with Phase Modulation for Multichannel OAM Vortex Beams Generation and Switching

Multichannel orbital angular momentum (OAM) generation based on metasurfaces has brought significant advancements in expanding communication capacity. However, the realization of truly integrated optics is still challenging and important aspects such as beam scanning and rapid electronic switching among OAM channels, which are crucial for broad-area communication coverage, have received little attention until now. Herein, a novel concept for multichannel OAM vortex beams generation and switching is proposed, realized by a guided-wave-excited metasurface (GWEM) in conjunction with a single pole five throws (SP5T) RF switch. A holography-based theory is developed and employed to complete the array synthesis and analysis procedure without the need for a 2 pi phase modulation. As a proof of concept, a prototype of the GWEM is experimentally demonstrated with high qualities, including the generation of five channels of OAM vortex beams with a scanning range of +/- 35 degrees in the elevation plane, a measured OAM mode purity of up to 84.5%, and consistent maintenance of the topological charge l = 2 state from 25 to 27 GHz. The proposed strategy features cost-effectiveness, compactness, and fast nanosecond-scale electronic switching for multichannel OAM vortex beams, making it highly applicable in space-limited automotive radar, imaging, and communication systems. Beam scanning or rapid electronic switching among orbital angular momentum (OAM) channels are crucial for broad-area communication coverage, while low cost, size, weight, and power consumption (C-SWaP) properties are imperative for automotive radar and imaging systems. In this work, a novel concept for multichannel OAM vortex beams generation and switching realized by a guided-wave-excited metasurface is proposed.image

Automated summary

Multichannel orbital angular momentum (OAM) generation and switching based on guided-wave-excited metasurface (GWEM) and RF switch is proposed as a novel concept. The experimental results show that this method can generate multiple OAM vortex beams and achieve rapid electronic switching. The proposed method is cost-effective, compact, and highly applicable.