Two-photon absorption properties of a novel class of triarylamine compounds

► We studied the two-photon absorption spectrum of new triarylamine compounds using femtosecond pulses. ► We observed an additional two-photon absorption band, located at around 900 nm, only for triarylamine with azoaromatic units. ► Changes in molecular symmetry brought about by the azoaromatic unit allow the first-excited state to be accessed by both one- and two-photon absorption, which was not observed for regular triarylamine compounds.