We have developed the first experimental method to quantitatively measure the optical absorption of an individual nanoparticle at very high-pressure (~10 GPa). This experiment was made possible by the development of an original approach, combining the "spatial modulation spectroscopy" technique (for single nanoparticle detection) with a "miniaturized" diamond anvil cell specifically tailored for these researches. Both optical and mechanical challenges had to be met before one could observe the effect of high pressure on the optical response of a single metallic nanoparticle, exhibiting a marked non-linear red-shift of its surface plasmon resonance under mechanical constraints. This study opens the way to the area of plasmonic straintronics.
This article was the subject of a Scientific News of the INP published on 11/02/2019.