High sensitivity and large scanning range optical antennas enabled by multi-casting ridge-waveguide subwavelength structure arrays

TL;DR

This paper presents a novel optical antenna design using subwavelength ridge-waveguide structures that achieves high sensitivity and a large scanning range, improving beam control in integrated photonics.

Contribution

It introduces a multi-casting ridge-waveguide grating antenna with enhanced longitudinal scanning and wavelength sensitivity, demonstrating significant improvements over traditional designs.

Findings

Achieved a far-field beam divergence of 0.13° and wavelength sensitivity of 0.237°/nm.

Demonstrated a large scanning range of up to 42.6° with multi-casting design.

Showed improved longitudinal wavelength sensitivity compared to typical waveguide grating antennas.

Abstract

With the rapid development of large-scale integrated photonics, optical phased array (OPA) is an effective way to realize highly integrated, stable and low-cost beam control system. Achieving a large field of view (FOV) in the longitudinal direction without increasing fabrication cost and system complexity is still a significant challenge in OPA antennas. Here, a high sensitivity and large scanning range antenna based on subwavelength structure array is proposed to enhance the longitudinal scanning and free-space radiating efficiency by using the ridge-waveguide structure and backward-emitting. A millimeter-long grating antenna with a far-field beam divergence of 0.13{\deg} and a wavelength sensitivity of 0.237{\deg}/nm is experimentally demonstrated. Furthermore, by using different sideband periods, we introduce a multi-casting grating antenna with a large scanning range up to 42.6{\deg}. The proposed devices show significant improvement in longitudinal wavelength sensitivity compared with the typical waveguide grating antennas.