title: Large third-order optical nonlinearity of self-assembled porphyrin oligomers.
abstract: Third-order nonlinear optical properties of two series of self-assembled porphyrin wires, one being terminated by zinc porphyrin and the other by free base porphyrin, were measured by femtosecond time-resolved optical Kerr effect. The hyperpolarizability values of the latter series were extremely large ranging from 10-30 to 10-29 esu, 10 times larger than the former. The behavior is accounted for by the contribution of terminal free base porphyrin to enhance the molecular polarization by acceptor nature toward central metalloporphyrin array.
authors.affiliation: Graduate School of Materials Science, Nara Institute of Science and Technology, CREST, Japan Science and Technology Corporation, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Ogawa
authors.forename: Tieqiao
authors.initials: T
authors.lastname: Zhang
authors.forename: Keitaro
authors.initials: K
authors.lastname: Yoshihara
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kobuke