Multifunctional Optical Vortex Beam Generator via Cross-Phase Based on Metasurface

Abstract

We propose a multifunctional optical vortex beam (OVB) generator via cross-phase based on a metasurface. Accordingly, we separately investigate the two different propagation characteristics of OVB modulated by the low-order cross-phase (LOCP) and the high-order cross-phase (HOCP) in a self-selected area. When LOCP modulation is added to OVB, topological charges can be measured for any order of OVB. Moreover, we achieve the rotation tunable performance successfully by adding the rotation component. Then, we realize the function of polygonal beam generation and singularities regulation with the HOCP. The order of the HOCP is exactly equal to the number of a polygon OVB’s sides. The waist radius and usable width of the beam lengthens as the distance of the self-selected area increases. When the conversion rate is doubled, the distance between singularities widens by about 0.5 μm. The proposed OVB generator provides a simple strategy for detecting the value of topological charges and achieving OVB shaping and singularity manipulation simultaneously. We hope this can open new horizons for promoting the development of photon manipulation, optical communication, and vortex beam modulation.

Polarization-multiplexing graphene-based coding metasurface for flexible terahertz wavefront control

“…In comparison, graphene has recently garnered significant attention due to its wide range of tunable conductivities, fast response speed, and polarization independence [29,30]. It has been extensively used to fabricate various tunable terahertz meta-devices, including reconfigurable specialized beam generators, tunable meta-lenses, controllable metacouplers, and so on [31][32][33][34][35][36][37][38][39]. Whereas, most existing graphene-based coding metasurfaces can only respond to a single polarization mode of the incident wave, which is considerably unfavorable for high integration and large capacity of terahertz communication [40][41][42][43].…”

Arbitrary-Order and Multichannel Optical Vortices with Simultaneous Amplitude and Phase Modulation on Plasmonic Metasurfaces

“…Optical metasurfaces are a kind of ultrathin planar optical element, which are composed of one or several layers of artificial structures assembled from traditional materials [19][20][21]. Through careful design of each element structure, the metal metasurfaces can provide an additional phase gradient or surface momentum [22,23].…”