Our paper Pulsed Molecular Optomechanics in Plasmonic Nanocavities: From Nonlinear Vibrational Instabilities to Bond-Breaking has just been published in Physical Review X (Open Access)!
It’s a part of our effort to verify the predictions of the optomechanical picture of Raman Scattering from molecules, which was first proposed by researchers from EPFL, and further developed in my former group, headed by Javier Aizpurua in San Sebastian in Basque Country, in collaboration with Geza Giedke and Alejandro Gonzalez-Tudela.
The paper reports and discusses nonlinearities observed in Raman scattering from molecules positioned in well-controlled plasmonic nanosystems, which have been extensively studied by the research groups of Jeremy Baumberg at Cambridge University. While these systems are rather easy to destroy by a strong continuous laser illumination, Anna Lombardi, the lead author of the paper, found that one can instead use picosecond pulses of a much more intense laser source to stimulate the vibrations of the molecules.
Furthermore, she observed that the amount of light scattered off the molecules in the Raman process does not scale linearly with the peak intensity of the lasers! Instead, in accordance with the predictions of the Molecular Optomechanical, the Raman scattering becomes superlinear after a certain threshold.