Showing papers by "Sophie Brasselet published in 1997"
TL;DR: In this article, the aging time of the sol and the thermal treatment of the coatings are both important to improve the second-harmonic-generation (SHG) response and its temporal stability.
Abstract: Hybrid organic−inorganic nanocomposites have been synthesized through hydrolysis and co-condensation between (4-(amino-N,N-(diethoxydiurethano)propyltriethoxysilane)-2-methyl-4‘-nitroazobenzene (ICTES−Red 17) and tetramethoxysilane (TMOS). From the resulting sols, coatings a few microns in thickness can be deposited. It has been shown that the aging time of the sol and the thermal treatment of the coatings are both important to improve the second-harmonic-generation (SHG) response and its temporal stability. The hybrid coatings 4.2 μm thick, with a 50/50 ICTES−Red 17-TMOS molar composition, exhibit the highest nonresonant SHG response (d33 = 150 pm/V, λ = 1.34 μm) reported up to now for sol−gel-derived NLO materials. Moreover, they also exhibit a good stability at 80 °C.
98 citations
TL;DR: A purely octupolar polarization-independent photoinduced second-harmonic-generation response in a Dispersed Red 1-methyl methacrylate thin film is found and is not within the reach of the classical electric-field poling technique.
Abstract: We demonstrate the possibility of controlling the symmetry properties of photoinduced χ2 macroscopic susceptibility in polymer films. Ellipsometric adjustment of the write beams allows one to monitor the macroscopic χ2 symmetry from a dipolar to an octupolar configuration. Experimental results are in agreement with an irreducible spherical tensor-based model jointly applied to the molecular β hyperpolarizability and field tensors. We found a purely octupolar polarization-independent photoinduced second-harmonic-generation response in a Dispersed Red 1–methyl methacrylate thin film. Such a configuration, as generated by an octupolar tensor write field tensor made up of counterclockwise circularly polarized ω and 2ω beams, is not within the reach of the classical electric-field poling technique.
51 citations
TL;DR: The title compound has a C−H···O hydrogen bond-mediated trigonal network structure that leads to octupolar NLO behavior in the solid state as discussed by the authors. But this is not the case for all NLO compounds.
50 citations
11 citations
01 Jan 1997
TL;DR: In this paper, a C-H...O H bond-mediated trigonal network structure that leads to octupolar NLO behavior in the solid state was proposed. But it was not shown in practice.
Abstract: The title compd. has a C-H...O H bond-mediated trigonal network structure that leads to octupolar NLO behavior in the solid state.
3 citations
Proceedings Article•
18 May 1997