Relaxation kinetics of photoinduced surface relief grating on azopolymer films

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Tatsunosuke Matsui, Shin-ichiro Yamamoto, Masanori Ozaki, Katsumi Yoshino, and Francois Kajzar, Journal of Applied Physics 92, 6959 (2002) and may be found at https://doi.org/10.1063/1.1516264

DNA - novel nanomaterial for applications in photonics and in electronics

Functionalization with surfactants and with active molecules of deoxyribonucleic acid (DNA), thin film processing as well as their nonlinear optical and electrical properties are reviewed and discussed. On the basis of a quantum three level model, we show that the anomalous concentration variation of cubic susceptibility chi((3))(-3 omega; omega, omega, omega) in thin films of DNA-CTMA complexes doped with Disperse Red 1 chromophore can be explained by the concentration variation of two-photon resonance contribution. We show also that the DNA complexes, plasticized with glycerol and adequately doped can be processed into self standing conducting membranes with a high electrical conductivity. The measured ionic conductivity at room temperature, depending on dopant used and its concentration, is in the range of 3.5 x 10(-4)-10(-5) S/cm and increases linearly as a function of temperature, reaching 10(-3) S/cm at 358 K for the most conducting sample, obeying predominantly the Arrhenius law. Practical applications of DNA complexes are also described and discussed. (C) 2012 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.Romanian Ministry of Education, Research, Youth and Sports, through the UEFISCDI organismRomanian Ministry of Education, Research, Youth and Sports, through the UEFISCDI organism [279/7.10.2011, PN-II-ID-PCE-2011-3-05053]AFOSRAFOSRFAPESPFAPESPCNPqCNPqCAPESCAPE

Second order nonlinear optical properties of poled films containing azobenzenes tailored with azulen-1-yl-pyridine

Azo compounds, which are highly versatile molecules, have attracted a considerable attention both for their fundamental properties and for practical applications, especially in photonics. The conjugated azo-aromatic systems containing 4-(R-azulen-1-yl)-2,6-dimethyl-pyridine were investigated for their nonlinear optical properties. These molecules were embedded in polymethyl methacrylate (PMMA) matrix, and the obtained guest-host systems were processed into good optical quality thin film by spin coating technique. The dipolar moments of dissolved in PMMA molecules were oriented by applying a high DC electric field at a temperature close to the polymer glass transition temperature. The second - order nonlinear optical (NLO) properties of poled films were studied by the optical second harmonic generation technique (SHG). The poling kinetics, studied by in situ SHG as well as the measured second-order NLO susceptibilities of poled films are reported and discussed

Etude par dischroisme lineaire en infrarouge et resonance paramagnetique electronique de couches monomoleculaires organiques de diacetylene

SIGLEAvailable from CEN Saclay, Service de Documentation, 91191 Gif-sur-Yvette Cedex (France) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Luminescence Lifetime Temperature Sensing Based on Sol-Gels and Poly(acrylonitrile)s Dyed with Ruthenium Metal–Ligand Complexes

Temperature-sensitive materials based on the temperature probe ruthenium-tris-1,10-phenathroline (Ru(phen)) are presented. As its luminescence, the intensity and decay time of which are both temperature sensitive, is quenched by oxygen, Ru(phen) needs to be encapsulated in materials with very low permeability to molecular oxygen. Its incorporation into sol-gels and poly(acrylonitrile)s (PANs) is investigated here and it is shown that the resulting materials can be deposited onto optical fibers for use as temperature optodes

Nonlinear optical properties of benzylic amide [2] catenanes: a novel versatile photonic material

Benzylic amide catenanes are a class of synthetically-accessible interlocked molecular rings which can rotate one through the other depending on the nature of the local environment. The rings contain four phenyl units each and interlocking also affords their packing in novel, highly interacting ways that may lead to unexpected properties thus opening up the possibility of developing new materials. Third harmonic generation in benzylic amide catenane solutions was measured at a wavelength of γ = 1064 nm, with the fundamental and the harmonic wavelengths in the region of transparency of the material. The thoroughly non resonant value of the hyperpolarisability γ(-3ω; ω, ω, ω) was found to be (6.5 ± 0.7) 10-35 esu with a negligible imaginary part, in agreement with the value of (6.8 ± 0.9) 10-35 esu calculated from a bond-additivity model of hyperpolarisability. The static second order hyperpolarisability predicted by a Molecular Orbital model was about a factor four less than the experimental value. Second hyperpolarizability values of several solvents were also measured at the fundamental wavelength of γ = 1064 nm