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Conference on Lasers and Electro-Optics

Entangled Two-Photon Absorption in Commercial Fluorophores

Tobias Bernd Gäbler, Nitish Jain, Josué R. León Torres, P.J. Hendra, Markus Gräfe

Published Jan 1, 2021• 1 citation
Publisher

Abstract

Our study addresses the applicability of simple and common fluorophores for entangled two-photon fluorescence microscopy. Using CW-pumped SPDC waveguides, we can measure linear absorption rates of entangled photons in standard fluorophores in life science.
DOI
10.1364/cleo_si.2021.sw3d.3

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Excitation with entangled photon pairs may lead to an increase in the efficiency of two-photon absorption at low photon flux. The corresponding process, entangled two-photon absorption (E2PA), has been investigated in numerous theoretical and experimental studies. However, significant ambiguity and inconsistency remain in the literature about the absolute values of E2PA cross sections. Here, we use a fluorescence-based registration scheme to experimentally determine upper bounds on the cross sections for six fluorophores. These bounds are up to 4 orders of magnitude lower than the smallest published cross section. For two samples that have been studied by others, Rhodamine 6G and 9R-S, we measure upper bounds 4 and 5 orders of magnitude lower than the previously reported cross sections.
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