Superresolution imaging of two incoherent optical sources with unequal brightnesses

TL;DR

This paper investigates the fundamental limits of resolving two incoherent optical sources with unequal brightnesses, comparing measurement schemes and identifying near-optimal strategies for high-precision separation estimation.

Contribution

It extends superresolution imaging analysis to sources with unequal brightnesses and evaluates measurement schemes against quantum limits.

Findings

Gaussian mode measurement is nearly optimal for small separations.

The quantum Fisher information sets the ultimate precision limit.

Comparison of measurement schemes highlights practical approaches.

Abstract

Resolving the separation between two incoherent optical sources with high precision is of great significance for fluorescence imaging and astronomical observations. In this paper, we focus on a more general scenario where two sources have unequal brightnesses. We give the ultimate precision limit with respect to separation by using the quantum Fisher information. Through the calculation of the classical Fisher information, we analyze and compare several specific measurement schemes including direct measurement, Gaussian mode measurement and zero-photon measurement. The results indicate that Gaussian mode measurement is the nearly optimal for a small separation. Our work provides a positive complement to the aspect of superresolution imaging of incoherent sources.