Our group has recently published a paper on the giant optomechanical spring effect in plasmonic nano- and picocavities probed by surface-enhanced Raman scattering. The extreme confinement provided by plasmonic nano- and pico-cavities enhances the optomechanical coupling to access a very large optical spring effect in single molecules under continuous illumination.
Full publication at: https://www.nature.com/articles/s41467-023-38124-1