%0 Journal Article %T Nanoscale multipolar chromophores for optical limiting in the visible-NIR range based on multiphoton absorption %+ Laboratoire de d'ElectroSynthèse et Synthèse Organiques (SESO) %+ Neurophysiologie et nouvelles microscopies (NNM (UM 82)) %+ Laboratoire de Neurophysiologie et Nouvelles Microscopies (U1128) %A Mongin, Olivier %A Charlot, Marina %A Katan, Claudine %A Porrès, Laurent %A Parent, Manuel %A Pons, Thomas %A Mertz, Jerome %A Blanchard-Desce, Mireille %< avec comité de lecture %@ 0277-786X %J Proceedings of SPIE, the International Society for Optical Engineering %I SPIE, The International Society for Optical Engineering %S Nonlinear Optical Transmission and Multiphoton Processes in Organics II %V 5516 %P 9-20 %8 2004-10-15 %D 2004 %R 10.1117/12.559937 %K Two-photon absorption %K multipolar structures %K nanoscale systems %K branched-structures %K optical limitation %Z Chemical Sciences/Theoretical and/or physical chemistryJournal articles %X A series of structurally-related multipolar chromophores of different symmetry (dipolar, quadrupolar, octupolar, dendritic…), and shape (rod-like, Y-shaped…) propeller-shaped, were investigated for optical power limiting based on multiphoton absorption processes. Their design is based on the functionalization of nanoscale linear or branched conjugated backbones with electro-active (i.e. electron-releasing or electron-withdrawing) peripheral and core/node groups. Their two-photon absorption (TPA) spectra were determined by investigating their two-photon-excited fluorescence properties in the NIR region using pulsed excitation in the femtosecond regime. These studies provide evidence that the charge symmetry plays an important role, the quadrupolar chromophores leading to giant TPA cross-sections in the visible red. Furthermore, modulation of the nonlinear absorptivity/transparency/photostability trade-off can be achieved by playing on the nature of the electroactive groups and of the spacers. Interestingly, higher-order charge symmetries and branched structures provide an innovative route for TPA amplification and/or spectral broadening in the NIR region. %G English %2 https://univ-rennes.hal.science/hal-01417574/document %2 https://univ-rennes.hal.science/hal-01417574/file/SPIE2004HAL.pdf %L hal-01417574 %U https://univ-rennes.hal.science/hal-01417574 %~ UNIV-PARIS5 %~ UNIV-RENNES1 %~ CNRS %~ UR1-HAL %~ TEST-UNIV-RENNES %~ TEST-UR-CSS %~ UNIV-RENNES %~ UNIV-PARIS