Nano-optical phenomena of van der Waals materials

Nano-optics is a frontier of research that explores light-matter interactions in the nanometer length scale. In this talk, we present nano-optical studies of van der Waals (vdW) coupled layered materials using the state-of-the-art scanning near-field optical microscopy – a powerful technique allowing high resolution nano-imaging and nano-spectroscopy in a wide spectral range from infrared to visible. With this powerful tool, we observed and characterized in real space various polaritonic modes in vdW materials, including plasmon polaritons in graphene (layers) [1-3], phonon polaritons in hBN [4], and exciton polaritons in group IV transition metal dichalcogenides [5]. Novel physics and potential applications associated with these polaritonic modes will be discussed.