Quantum photon correlations as a resource in superresolution microscopy

Place: IMDEA Nanociencia conference hall.

Abstract: 

Far-field optical microscopy beyond the Abbe diffraction limit, making use of nonlinear excitation (e.g. STED), or temporal fluctuations in fluorescence (PALM, STORM, SOFI) is already a reality.
In contrast, overcoming the diffraction limit using non-classical properties of light is very difficult to achieve due to the difficulty in generating quantum states of light and their inherent fragility.
Here, we experimentally demonstrate practical superresolution microscopy based on quantum properties of light naturally emitted by fluorophores used as markers in fluorescence microscopy. Our approach is based on photon antibunching, the tendency of fluorophores to emit photons one by one rather than in bursts.
Since the non-classical intensity correlations carry higher spatial frequency information, they can be utilized to enhance image resolution.
We demonstrate how antibunching can improve the resolution capabilities of image-scanning confocal microscopy in all three dimensions. Finally, we show that these methods are compatible with currently developed SPAD arrays, serving as small single-photon imaging detectors, and thus require little infrastructure investment.