Photonic Terahertz Phased Array

TL;DR

This paper presents a novel photonic platform for broadband terahertz phased arrays using a 2D phase coding metasurface, enabling precise control and steering of THz signals across a broad frequency range.

Contribution

Introducing a photonic approach with a pixelated nonlinear metasurface for 2D phase control in THz phased arrays, overcoming previous high-frequency and broadband limitations.

Findings

Effective single and dual beamforming demonstrated.

Successful imaging and vortex beam generation.

Broadband operation from 0.8 to 1.4 THz achieved.

Abstract

Phased arrays are crucial in various technologies, such as radar and wireless communications, due to their ability to precisely control and steer electromagnetic waves. This precise control improves signal processing and enhances imaging performance. However, extending phased arrays to the terahertz (THz) frequency range has proven challenging, especially for high-frequency operation, broadband performance, two-dimensional (2D) phase control with large antenna arrays, and strong phase modulation. Here, we introduce a photonic platform to realize a THz phased array that bypasses the above challenges. Our method employs 2D phase coding with 2-bit across a broad THz frequency range from 0.8 to 1.4 THz. The core of our design is a pixelated nonlinear Pancharatnam-Berry metasurface driven by a spatially modulated femtosecond laser, allowing precise phase control of THz signals. We showcase the effectiveness of our method through four proof-of-concept applications: single beamforming, dual beamforming, imaging and vortex beam generation. The realized photonic platform provides a promising pathway for developing broadband phased arrays in the THz regime.