title: Highly efficient third-order optical nonlinearities in donor-substituted cyanoethynylethene molecules.
abstract: We investigated the third-order nonlinear optical properties of several donor-substituted cyanoethynylethene molecules in the zero-frequency limit. We observed nonlinearities that are extraordinarily large relative to the small molecular mass of these molecules and that are within a factor of 50 from the fundamental limit. At a wavelength of 1.5 microm, the rotational average of the third-order molecular polarizability is 53 +/- 13 x 10(-48) m5 V(-2) (3.8 x 10(-33) esu) for the best molecule, which corresponds to 1.7 x 10(-48) m5 V(-2) per delocalized electron. The high nonlinear efficiency of these molecules is due to the compact two-dimensional conjugated system and the effective donor-acceptor substitution patterns.
authors.affiliation: Department of Physics and Center for Optical Technologies, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
authors.forename: Joshua C
authors.initials: JC
authors.lastname: May
authors.forename: Jin H
authors.initials: JH
authors.lastname: Lim
authors.forename: Ivan
authors.initials: I
authors.lastname: Biaggio
authors.forename: Nicolle N P
authors.initials: NN
authors.lastname: Moonen
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Michinobu
authors.forename: François
authors.initials: F
authors.lastname: Diederich