title: Linear and circular dichroism in porphyrin J-aggregates probed by polarization modulated scanning near-field optical microscopy.
abstract: Polarization modulated scanning near-field optical microscopy (PM-SNOM) is effective in detecting circular and linear dichroism with sub-wavelength resolution. PM-SNOM investigation of the chiroptical properties of single ribbon-like nanosized J-aggregates formed by acid induced aggregation of tris-(4-sulfonatophenyl)phenylporphyrin is reported. Linear dichroism maps give evidence of well-organized chromophores packed in linear arrays within the structure of the nanoribbons. Circular dichroism maps indicate that the molecules forming the nanoribbon have an inherently chiral structure at the local scale.
authors.affiliation: Dipartimento di Fisica "Enrico Fermi" and CNISM, Università di Pisa, Istituto Nazionale di Ottica INO-CNR, Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Tantussi
authors.forename: Francesco
authors.initials: F
authors.lastname: Fuso
authors.forename: Maria
authors.initials: M
authors.lastname: Allegrini
authors.forename: Norberto
authors.initials: N
authors.lastname: Micali
authors.forename: Ilaria Giuseppina
authors.initials: IG
authors.lastname: Occhiuto
authors.forename: Luigi Monsù
authors.initials: LM
authors.lastname: Scolaro
authors.forename: Salvatore
authors.initials: S
authors.lastname: Patanè