A collaborative research team has successfully visualized in real space the ultrafast optical modulation of hyperbolic phonon polaritons (HPhPs) in a van der Waals heterostructure composed of hBN and WS2. The research is published in the journal Nano Letters, and was led by Kazuki Kamada of the Institute for Molecular Science (IMS) and Osaka Metropolitan University, along with Dr. Jun Nishida, assistant professor at IMS, and Takashi Kumagai, associate professor at IMS.
HPhPs are hybrid light-matter modes formed through strong coupling between infrared electromagnetic fields and optical phonons in a material. Their hybrid character allows them to coherently transport electromagnetic energy while confining it to spatial scales far below the wavelength of light in free space. These properties make HPhPs promising for nanoscale light manipulation, high-sensitivity spectroscopy and future nanophotonic technologies. Dynamically controlling HPhPs at ultrafast speeds could provide an important foundation for active nanoscale optical devices.