Spontaneous Scattering of Raman Photons from Cavity-QED Systems in the Ultrastrong Coupling Regime

Abstract

We show that spontaneous Raman scattering of incident radiation can be observed in cavity-QED systems without external enhancement or coupling to any vibrational degree of freedom. Raman scattering processes can be evidenced as resonances in the emission spectrum, which become clearly visible as the cavity-QED system approaches the ultrastrong coupling regime. We provide a quantum mechanical description of the effect, and show that ultrastrong light-matter coupling is a necessary condition for the observation of Raman scattering. This effect, and its strong sensitivity to the system parameters, opens new avenues for the characterization of cavity QED setups and the generation of quantum states of light.

Mapping the Optomechanical Coupling Mediated by Light among Mechanical Resonators Including Multilayer Cavity and Molecules

“…The cavity and the molecules work as mechanical resonators with significantly different typical frequencies (several megahertz for the cavity and a few tens of gigahertz for the molecules), on which the capability of sensitive probing and interaction of the system with the surrounding environment depends. Furthermore, in the form of SPPs, the light hybridizes the cavity, couples the molecule, and triggers the plasmon–exciton coupling, displaying the molecular vibrational modes and disclosing a region rich in molecular Raman transitions, − because of an enhanced sensitivity on the molecular analysis derived by the behavior of the plasmonic sensor.…”