Optical phased arrays for LIDAR: beam steering via tunable plasmonic metasurfaces

TL;DR

This paper introduces a plasmonic pixel design using a metallic nanoantenna and conductive oxide for optical phased arrays, enabling dynamic beam steering in LIDAR with over 330° phase control.

Contribution

It proposes a novel plasmonic pixel design with voltage-controlled phase modulation for improved LIDAR beam steering capabilities.

Findings

Phase control range exceeds 330° with constant magnitude.

Simulations demonstrate effective beam steering in LIDAR applications.

Strategies proposed for dual-band operation and maximizing reflection magnitude.

Abstract

Controlling the phase and amplitude of light emitted by the elements (i.e., pixels) of an optical phased array is of paramount importance to realizing dynamic beam steering for LIDAR applications. In this paper, we propose a plasmonic pixel composed of a metallic nanoantenna covered by a thin oxide layer, and a conductive oxide, e.g., ITO, for use in a reflectarray metasurface. By considering voltage biasing of the nanoantenna via metallic connectors, and exploiting the carrier refraction effect in the metal-oxide-semiconductor capacitor in the accumulation and depletion regions, our simulations predict control of the reflection coefficient phase over a range $>330^{\circ}$ with a nearly constant magnitude. We discuss the physical mechanism underlying the optical response, the effect of the connectors, and propose strategies to maximize the magnitude of the reflection coefficient and to achieve dual-band operation. The suitability of our plasmonic pixel design for beam steering in LIDAR is demonstrated via 3D-FDTD simulations.