Enhanced two-photon absorption of frequency-entangled N00N states in type-I SPDC

We study the two-photon absorption properties of frequency-entangled N00N states produced in a Hong-Ou-Mandel interferometer using type-I degenerate photon pairs, generated via spontaneous parametric down-conversion. By comparing our results with N00N states with no frequency entanglement, we demonstrate enhanced two-photon absorption due to frequency entanglement. We also derive an analytic expression for the enhancement factor which is found to be greater than one for all finite values of the ratio of the bandwidth of the pump to the bandwidth of the detected photons. We have also found suppression and enhancement in the two-photon absorption probabilities for specific time delays applied to the N00N states. (paper)