title: Optical sum-frequency emission from langmuir-blodgett films of variable thickness: effects of the substrate and polar orientation of fatty acids in the films.
abstract: The nonlinear optical response arising from a model multilayer structure, i.e., Langmuir-Blodgett (LB) films comprised of different numbers of per-protonated (H) and per-deuterated (D) fatty acid layers on solid substrates, has been evaluated by sum-frequency generation (SFG) spectroscopy. The SFG signals depend significantly on the absolute polar orientation of the fatty acids in the individual layers and on the nonlinear optical response of the substrate. The SFG spectra on gold and fused quartz substrates demonstrate a totally different dependence on the number of the contributing H layers, which it is possible to analyze quantitatively. The results provide important information for understanding the origin of the nonlinear optical responses from ordered systems composed of multiple interfaces and therefore for extracting exact structural information about each interface from the observed SFG signals.
authors.affiliation: Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Nishida
authors.forename: C Magnus
authors.initials: CM
authors.lastname: Johnson
authors.forename: Jasper
authors.initials: J
authors.lastname: Holman
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Osawa
authors.forename: Paul B
authors.initials: PB
authors.lastname: Davies
authors.forename: Shen
authors.initials: S
authors.lastname: Ye