07/31/2025 LISE 303 12:30pm

Light–matter interaction at the nanoscale offers unprecedented opportunities to manipulate optical fields and material properties with high precision. In this seminar, I will present two recent advances along this direction. First, I will discuss the observation of visible-frequency hyperbolic plasmon polaritons in thin films of MoOCl₂, a natural van der Waals crystal, achieving low-loss, in-plane hyperbolicity without the need for engineered metamaterials. This platform enables extreme light confinement and opens pathways for super-resolution imaging and optoelectronic applications at visible wavelengths.

Second, I will introduce a novel approach for ultrafast manipulation of light’s orbital angular momentum (OAM) via Fourier space-time transformations, achieving subcycle control on femtosecond timescales. By engineering azimuthal space-time couplings in ultrashort pulses, we demonstrate self-torque and angularly accelerating wave packets, opening new perspectives for ultrafast spectroscopy, light-matter interaction, and nanostructure manipulation. Together, these results highlight new strategies for advancing the control of optical fields in both spatial and temporal domains, with implications across nanophotonics and quantum materials research.