Quantum Theory of Superresolution for Two Incoherent Optical Point Sources

TL;DR

This paper demonstrates that quantum measurement techniques can achieve superresolution in optical imaging, surpassing Rayleigh's criterion, by accurately estimating the separation of two incoherent sources using linear optics and photon counting.

Contribution

It introduces a quantum optical approach that enables superresolution for incoherent sources, challenging the traditional limits set by Rayleigh's criterion.

Findings

Quantum measurements can estimate source separation with high precision.

Superresolution is achievable for both fluorophores and stars.

Rayleigh's criterion is not a fundamental limit in quantum optical measurements.

Abstract

Rayleigh's criterion for resolving two incoherent point sources has been the most influential measure of optical imaging resolution for over a century. In the context of statistical image processing, violation of the criterion is especially detrimental to the estimation of the separation between the sources, and modern farfield superresolution techniques rely on suppressing the emission of close sources to enhance the localization precision. Using quantum optics, quantum metrology, and statistical analysis, here we show that, even if two close incoherent sources emit simultaneously, measurements with linear optics and photon counting can estimate their separation from the far field almost as precisely as conventional methods do for isolated sources, rendering Rayleigh's criterion irrelevant to the problem. Our results demonstrate that superresolution can be achieved not only for fluorophores but also for stars.