By Joel D. Cox, D-IAS Assistant Professor, SDU Nano Optics, The Mads Clausen Institute
Nanophotonics explores fundamental interactions between light and matter at the nanoscale, where classical electromagnetism intersects with quantum mechanics. Noble metal nanostructures supporting plasmons, collective free-electron oscillations that can focus light within nanometric volumes, well-below the diffraction limit imposed by conventional optics, are widely studied in nanophotonics for a plethora of applications ranging from biosensing to photochemistry and solar energy harvesting. Unfortunately, despite substantial progress in nanofabrication technologies, plasmons in conventional metal nanostructures are still hindered by their large ohmic losses and difficulty in actively tuning their properties.
Graphene—the atomically-thin carbon layer—has recently emerged as an appealing material platform for nanophotonics due to its many fascinating optical and electronic properties, launching extensive research efforts in two-dimensional material nanophotonics. Here I will discuss recent advances in the study of light-matter interactions in atomically-thin materials, with particular emphasis on graphene plasmons, which exhibit lower losses than their noble metal counterparts, can be electrically modulated, and enable extreme confinement of light down to atomic length scales, potentially advancing control of light by light towards the single-photon regime for emerging photonic and quantum optical technologies.