Super-resolution imaging based on active optical intensity interferometry

TL;DR

This paper introduces a novel active intensity interferometry method for super-resolution imaging over long distances, leveraging multiple laser sources and computational algorithms to surpass diffraction limits in outdoor environments.

Contribution

The work presents a new active intensity interferometry scheme that enables super-resolution imaging over kilometer ranges, overcoming limitations of traditional thermal light sources.

Findings

Successfully imaged millimeter-level targets over 1.36 km

Achieved 14 times the diffraction-limited resolution

Demonstrated robustness against atmospheric turbulence

Abstract

Long baseline diffraction-limited optical aperture synthesis technology by interferometry plays an important role in scientific study and practical application. In contrast to amplitude (phase) interferometry, intensity interferometry -- which exploits the quantum nature of light to measure the photon bunching effect in thermal light -- is robust against atmospheric turbulence and optical defects. However, a thermal light source typically has a significant divergence angle and a low average photon number per mode, forestalling the applicability over long ranges. Here, we propose and demonstrate active intensity interferometry for super-resolution imaging over the kilometer range. Our scheme exploits phase-independent multiple laser emitters to produce the thermal illumination and uses an elaborate computational algorithm to reconstruct the image. In outdoor environments, we image two-dimension millimeter-level targets over 1.36 kilometers at a resolution of 14 times the diffraction limit of a single telescope. High-resolution optical imaging and sensing are anticipated by applying long-baseline active intensity interferometry in general branches of physics and metrology.