Two-photon absorption of new multibranched chromophores based on bis(diphenylamino)stilbene

A series of new (E)-4,4′-bis(diphenylamino)stilbene derivatives have been synthesized to investigate nonlinear absorptivities with attention paid to the peripheral substituent effect and multibranched modification effect by the open aperture femtosecond Z-scan technique and the nanosecond nonlinear optical transmission (NLT), respectively. Comparing the two-photon absorptivity (TPA) observed of (E)-4,4′-bis(diphenylamino)stilbene (BDPAS) with those of its derivatives, we found that substituent group attached to the periphery of BDPAS has no obvious contribution to enhancement TPA and that the dramatic increase of effective TPA cross-sections of multibranched samples in nanosecond regime strongly suggests their larger excited-state absorption.