Fine-Tuning of Entangled Two-Photon Absorption by Controlling the One-Photon Absorption Properties of the Chromophore.

The detailed analysis of the sum-over-state formula for the entanglement-induced two-photon absorption (ETPA) transition moment shows that the magnitude of the ETPA cross-section is expected to vary significantly depending on the coherence time T and the relative position of just two electronic states. Moreover, the dependency on T is periodic. These predictions are confirmed by molecular quantum mechanical calculations for several chromophores.