Colóquio organizado pelo Departamento de Física acontece nesta sexta-feira (19)
Palestra será proferida pelo professor Pierre-François Brevet, do Institut Lumière Matière, Université Claude Bernard Lyon, da França
O Departamento de Física promoverá nesta sexta-feira (19), no auditório do próprio departamento, um colóquio que terá como tema “Second Harmonic Scattering in Liquids”. Apresentado pelo professor Pierre-François Brevet, do Institut Lumière Matière, Université Claude Bernard Lyon, da França, o evento começa às 16h.
Quadratic nonlinear optical processes entailing the conversion of two photons at a fundamental energy into one photon with the sum energy are gaining a wide interest over the years. These processes obey strict parity rules in order to occur. For instance, they are forbidden in media possessing inversion symmetry like liquids. This rule can however be of a fundamental importance to investigate the special cases where inversion symmetry is broken by a small amount. Second harmonic generation, the degenerate processes of photon addition, can thus be used to investigate the bulk of liquid phases as well as liquid interfaces and small scale aggregates, supramolecular assemblies and nanoparticles. Using second harmonic scattering, studies on the quadratic nonlinear optical response different liquid systems have been performed over the last years [1,2]. In particular, we have been able to observe the presence or absence of correlation between the liquid molecules. We will present three cases: a dye molecule dispersed in its solvent, molecular aggregates of the same dye molecules and finally focus on the case of water, where the salt induced long-to-short range orientation transition has been observed.
 G. Revillod, J. Duboisset, I. Russier-Antoine, E. Benichou, G. Bachelier, Ch. Jonin, P.F. Brevet, Multipolar Contributions to the Second Harmonic Response from Mixed DiA-SDS Molecular Aggregates, J. Phys. Chem. C, 112 (2008) 2716. J. Duboisset, P.F. Brevet, Salt Induced Long-to-Short Range Orientation Transition in Water, Phys. Rev. Lett., 120 (2018) 263001.
Secretaria de Pós-Graduação
Departamento de Física - UFPE