Integrated Microcomb-Driven Vortex Electromagnetic Waves for Broadband Forward-looking Sensing

TL;DR

This paper introduces a chip-scale microcomb-based microwave photonic system that generates broadband vortex electromagnetic waves with high mode purity, enabling advanced all-weather sensing and imaging beyond diffraction limits.

Contribution

It presents a novel integrated architecture using a dissipative Kerr soliton microcomb to synthesize broadband vortex EM waves with high mode purity on a chip.

Findings

Achieved 8 GHz bandwidth covering 18-26 GHz frequencies.

Generated 15 programmable orbital angular momentum modes.

Demonstrated superior imaging of point targets and complex scenes.

Abstract

Microwave sensing is a critical enabler for all-weather perception, yet its resolution is fundamentally capped by the diffraction limit of the physical antenna aperture. While vortex electromagnetic (EM) waves offer a route to bypass this barrier, practical deployment is constrained by the trade-off between bandwidth, mode purity, and hardware complexity. Here, we propose a microwave photonic architecture enabled by a chip-scale dissipative Kerr soliton (DKS) microcomb that resolves these constraints. The microcomb provides a grid of over 270 optical lines with linewidths below 30 kHz, which are modulated and optically processed to synthesize vortex waves covering 8 GHz (18-26 GHz) with 15 programmable orbital angular momentum (OAM) modes. In contrast to conventional parallel-laser systems, our approach reduces phase error and improves OAM mode purity, while condensing the multi-wavelength source onto a monolithic chip. We demonstrate superior forward-looking imaging performance, clearly resolving both point targets and complex scenes. This work establishes a scalable framework bridging integrated soliton physics with broadband microwave processing, paving the way for next-generation compact smart sensors.