Wide-spectrum optical synthetic aperture imaging via spatial intensity interferometry

TL;DR

This paper introduces a novel optical synthetic aperture imaging method using spatial intensity interferometry, enabling diffraction-limited, wide-spectrum, high-resolution imaging insensitive to phase fluctuations and optical path differences.

Contribution

The study proposes a new optical aperture synthesis technique based on spatial intensity interferometry that achieves diffraction-limited imaging with wide spectral bandwidth in a single shot.

Findings

Achieved diffraction-limited imaging with 100 nm spectral width.

Demonstrated insensitivity to optical path differences between sub-apertures.

Simulated and experimentally validated the method's effectiveness.

Abstract

High resolution imaging is achieved using increasingly larger apertures and successively shorter wavelengths. Optical aperture synthesis is an important high-resolution imaging technology used in astronomy. Conventional long baseline amplitude interferometry is susceptible to uncontrollable phase fluctuations, and the technical difficulty increases rapidly as the wavelength decreases. The intensity interferometry inspired by HBT experiment is essentially insensitive to phase fluctuations, but suffers from a narrow spectral bandwidth which results in a lack of detection sensitivity. In this study, we propose optical synthetic aperture imaging based on spatial intensity interferometry. This not only realizes diffraction-limited optical aperture synthesis in a single shot, but also enables imaging with a wide spectral bandwidth. And this method is insensitive to the optical path difference between the sub-apertures. Simulations and experiments present optical aperture synthesis diffraction-limited imaging through spatial intensity interferometry in a 100 $nm$ spectral width of visible light, whose maximum optical path difference between the sub-apertures reach $69.36\lambda$. This technique is expected to provide a solution for optical aperture synthesis over kilometer-long baselines at optical wavelengths.