Superresolution in interferometric imaging of strong thermal sources

TL;DR

This paper demonstrates that superresolution in interferometric imaging of strong thermal sources is fundamentally achievable beyond classical limits, using quantum estimation theory and specific measurement techniques.

Contribution

It introduces the quantum limit for resolving strong thermal sources and proposes measurement methods to attain this superresolution in interferometry.

Findings

Quantum limit for resolving strong thermal sources established

Measurement techniques proposed to achieve superresolution

Superresolution applicable to sources of any strength

Abstract

Imaging using interferometer arrays based on the Van Cittert-Zernike theorem has been widely used in astronomical observation. Recently it was shown that superresolution can be achieved in this system for imaging two weak thermal point sources. Using quantum estimation theory, we consider the fundamental quantum limit of resolving the transverse separation of two strong thermal point sources using interferometer arrays, and show that the resolution is not limited by the longest baseline. We propose measurement techniques using linear beam splitters and photon-number-resolving detection to achieve our bound. Our results demonstrate that superresolution for resolving two thermal point sources of any strength can be achieved in interferometer arrays.