TY - JOUR
AU - Alexander Mikhaylov
AU - Ryan Wilson
AU - Kristen Parzuchowski
AU - Michael Mazurek
AU - Charles Camp
AU - Martin Stevens
AU - Ralph Jimenez
AB - It has been proposed that entangled two-photon absorption (E2PA) can be observed with up to 10^10 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 ∼1060 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.
BT - The Journal of Physical Chemistry Letters
DA - 2022-02
DO - 10.1021/acs.jpclett.1c03751
IS - 6
M1 - 6
N1 - PMID: 35129354
N2 - It has been proposed that entangled two-photon absorption (E2PA) can be observed with up to 10^10 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 ∼1060 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.
PY - 2022
SP - 1489
EP - 1493
T2 - The Journal of Physical Chemistry Letters
TI - Hot-Band Absorption Can Mimic Entangled Two-Photon Absorption
UR - https://doi.org/10.1021/acs.jpclett.1c03751
VL - 13
ER -