Five-Photon Absorption and Selective Enhancement of Multiphoton Absorption Processes

Abstract

We study one-, two-, three-, four- and five-photon absorption of three centrosymmetric molecules using density functional theory. These calculations are the first ab initio calculations of five-photon absorption. Even- and odd-order absorption processes show different trends in the absorption cross sections. The behaviour of all even-and odd-photon absorption properties shows a semi-quantitative similarity which can be explained using few-state models. This analysis shows that odd-photon absorption processes are largely determined by the one-photon absorption strength whereas all even-photon absorption strengths are largely dominated by the two-photon absorption strength, in both cases modulated by powers of the polarizability of the final excited state. We demonstrate how to selectively enhance a specific multiphoton absorption process.