Nonlinear Spectroscopy and Multiphoton Processes in Molecules and Nanostructures
Ilaria Fortunati, Elisabetta Collini, Eleonora Garbin, Ida Ros, Francesco Todescato, Roberto Pilot, Camilla Ferrante, Raffaella Signorini and Renato Bozio
We provide a brief, introductory overview of current efforts to develop efficient multiphoton absorption materials. The central role of organic and metal-organic dyes characterized by excited states with intramolecular charge transfer character is emphasized and the basic features of essential state models frequently employed to rationalize one-photon and two-photon absorption (TPA) properties are outlined and critically discussed. The use of different strategies for enhancing the TPA cross section is exemplified by resorting to some recent results of collaborative research work carried out in our laboratory.
Keywords: Two-photon absorption, intramolecular charge transfer, essential states models, exciton models, quantum dots, plasmonic structures.