Integrated circular optical phased array

Qiankun Liu,Pavel Cheben,Tom Smy,Ahmad Atieh,Alejandro Sánchez-Postigo,Winnie N Ye

doi:10.1051/epjconf/202125501004

Abstract

Existing OPAs are typically based on 2D rectangular arrays or 1D linear arrays. Both approaches present a limited field-of-view (FOV) due to the presence of the grating lobes when the element spacing is larger than λ/2. To address the need for an increased steering range, we propose a new design strategy of an OPA system utilizing a 2D circular phased array, with a substantially increased FOV. We present a circular OPA using a demonstrated antenna element design, with an 820-element array. A steering range ΩSR calculated as a solid angle of 0.51π sr, and an angular beamwidth of 0.22°, was achieved. The array exhibits a sidelobe suppression larger than 10 dB, and a FOV of 2π sr. Although the performance is limited by the far field pattern of the individual antenna we chose, our circular OPA achieved, to the best of our knowledge, the largest steering range reported to date compared to the state-of-the-art integrated optical phased arrays reported in literature.

Highlights

In the last decade extensive research has been reported on static integrated optical phased arrays (OPAs) for solidstate beam steering with fast scanning and high resolution
The performance is limited by the far field pattern of the individual antenna we chose, our circular OPA achieved, to the best of our knowledge, the largest steering range reported to date compared to the state-of-the-art integrated optical phased arrays reported in literature
We present a new circular optical phased array design which provides an array factor with effectively suppressed grating lobes resulting an overall sidelobe suppression larger than 10 dB

Summary

Introduction

In the last decade extensive research has been reported on static integrated optical phased arrays (OPAs) for solidstate beam steering with fast scanning and high resolution. These OPA systems typically use either a 2D rectangular array of antennas [1, 2], or a 1D linear array of antennas with wavelength sweeping to achieve a two-dimensional beam steering [3,4,5,6,7]. The far field radiation pattern of a rectangular or linear array shows unavoidable strong grating lobes, when element spacing is larger than λ/2. These arrays demonstrate a restricted aliasingfree beam steering range, exhibiting a limited field-ofview (FOV). As a unique feature of circular arrays, the design shows a theoretical maximum FOV of 2π sr, due to the effective suppression of grating lobes

Beam formation and steering

Findings

Conclusion