Structure-to-property relations for two-photon absorption of hydrocarbon oligomers

Results from response theory calculations of various hydrocarbon oligomers predict that there is a common localization length, longer than for which the two-photon spectrum is dominated by a single state. The excitation energy of that state varies for the oligomer systems studied in the range of 1.4–1.8 times the optical band gap energy. Strong correlations between the intensity of this maximum two-photon state and the length of the oligomers are found.