  Recently, different experimental methods intended to detect the entangled
two-photon absorption (ETPA) phenomenon in a variety of materials have been
reported. The present work explores a different approach on which the ETPA
process is studied based on the changes induced in the visibility of a
Hong-Ou-Mandel (HOM) interferogram. By using an organic solution of Rhodamine B
as a model of nonlinear material interacting with entangled photons at 800 nm
region produced by spontaneous parametric down conversion (SPDC) Type-II, the
conditions that make possible to detect changes in the visibility of a HOM
interferogram upon ETPA are investigated. We support the discussion of our
results by presenting a model in which the sample is considered as a spectral
filtering function which fulfills the energy conservation conditions required
by ETPA, allowing to explain the experimental observations with good agreement.
We believe that this work represents a new perspective to studying the ETPA
interaction, by using an ultra-sensitive quantum interference technique and a
detailed mathematical model of the process.
