Localising two sub-diffraction emitters in 3D using quantum correlation microscopy

• Published in: New journal of physics Vol. 26; no. 3; pp. 33036 - 33051
• Main Authors: Li, Shuo, Li, Wenchao, Sun, Qiang, Moran, Bill, Brown, Timothy C, Gibson, Brant C, Greentree, Andrew D
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01-03-2024
• Subjects: Chemical compounds; Correlation; correlation microscopy; Cramer-Rao bounds; Cramér–Rao Lower Bound; Diffraction; Emitters; Localization; Lower bounds; maximum likelihood estimation; Maximum likelihood estimators; Microscopy; quantum optics; Simulation; super-resolution imaging; Three dimensional imaging; three-dimensional localisation
• ISSN: 1367-2630; 1367-2630
• DOI: 10.1088/1367-2630/ad31d4

Abstract
The localisation of fluorophores is an important aspect of determining the biological function of cellular systems. Quantum correlation microscopy (QCM) is a promising technique for providing diffraction unlimited emitter localisation that can be used with either confocal or widefield modalities. However, so far, QCM has not been applied to three dimensional localisation problems. Here we show that QCM provides diffraction-unlimited three-dimensional localisation for two emitters within a single diffraction-limited spot. By introducing a two-stage maximum likelihood estimator, our modelling shows that the localisation precision scales as
1
/
t
where
t
is the total detection time. Diffraction unlimited localisation is achieved using both intensity and photon correlation from Hanbury Brown and Twiss measurements at as few as four measurement locations. We also compare the results of (MC) simulations with the Cramér–Rao lower bound.