# Quasi-Continuous Metasurfaces for Orbital Angular Momentum Generation

## TL;DR

This paper introduces a quasi-continuous metasurface design that efficiently generates orbital angular momentum beams without the need for complex optimization, improving the quality and simplicity of OAM generation.

## Contribution

It presents a novel quasi-continuous metasurface design process that avoids local-response discontinuities, enabling high-quality OAM beam generation without scatterer optimization.

## Key findings

- Effective OAM generation at normal and oblique angles
- Elimination of scatterer optimization process
- Reduced distortions from local-response discontinuity

## Abstract

A quasi-continuous composite perfect electric conductor-perfect magnetic conductor metasurface and a systematic metasurface design process are proposed for the orbital angular momentum (OAM) generation. The metasurfaces reflect the incident left circularly polarized (LCP)/right circularly polarized (RCP) plane wave to RCP/LCP vortex beams carrying OAM at normal or oblique direction. Unlike conventional metasurfaces that are composed of discrete scatterers, the scatterers on the proposed metasurface form a quasi-continuous pattern. The patterning of the metasurface is calculated through grating vectors, and no optimization of single scatterer is required. Furthermore, the distortions from local-response discontinuity of discrete scatterers are avoided. This letter provides great convenience to high-quality OAM generation.