Hot-Band Absorption Can Mimic Entangled Two-Photon Absorption.
J Phys Chem Lett
; 13(6): 1489-1493, 2022 Feb 17.
Article
em En
| MEDLINE
| ID: mdl-35129354
ABSTRACT
It has been proposed that entangled two-photon absorption (E2PA) can be observed with up to 1010 lower photon flux than its classical counterpart, therefore enabling ultralow-power two-photon fluorescence microscopy. However, there is a significant controversy regarding the magnitude of this quantum enhancement in excitation efficiency. We investigated the fluorescence signals from Rhodamine 6G and LDS798 excited with a CW laser or an entangled photon pair source at â¼1060 nm. We observed a signal that originates from hot-band absorption (HBA), which is one-photon absorption from thermally populated vibrational levels of the ground electronic state. This mechanism, which has not been previously discussed in the context of E2PA, produces a signal with a linear power dependence, as would be expected for E2PA. For the typical conditions under which E2PA measurements are performed, contributions from the HBA process could lead to a several orders of magnitude overestimate of the quantum advantage.
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01-internacional
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MEDLINE
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En
Ano de publicação:
2022
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Article