Users from the University of North Florida and King’s College London collaborated with scientists in the Nanophotonics Group to show that closely spaced plasmonic gold nanorods produce an ultrafast transmission change when illuminated with a low-energy optical pulse. The ultrafast switching behavior is due to strong coupling between the nanorod plasmons, which are collective free-electron responses of metals that are driven by the incident light. The key discovery is that the closely spaced nanorod material exhibits nonlocality of the optical response, which has an unusually strong nonlinear dependence on incident light intensity. These materials belong to a new class of “metamaterials” – those with optical properties and responses that do not occur naturally. Electromagnetic modeling by University of Massachusetts collaborators confirms the nonlocal response of the plasmonic metamaterial.
This research may take the world a step closer towards developing optical components for super-fast computers and high-speed internet services. Transmitting information via light beams rather than electric currents could revolutionize data processing speeds. Until now, it has been difficult for light beams to interact with each other while traveling through a material. The new metamaterial with its designed nanorod stack structure allows light beams to interact efficiently and change intensity, thereby offering the potential for information to be sorted by beams of light at very high speeds.