In this talk, I will introduce two emerging optical nanoscopy techniques and the new science they enable. These techniques, namely magneto-scanning near-field optical microscopy (m-SNOM) and BOlometric Superconducting Optical Nanoscopy (BOSON), can dramatically expand our ability to probe quantum materials at the nanoscale. Using m-SNOM, we demonstrate Landau-level nanoscopy that directly visualizes Landau quantization and magneto-polariton formation. A waveguide quantum electrodynamics (QED) framework reveals spatially resolved hybridization between magnetic excitations and phonon polaritons, yielding universal scaling behaviors and design principles for cavity metastructures with tunable light–matter coupling. With BOSON, we integrate superconducting transition-edge sensors with near-field optics to achieve ultra-sensitive detection of nano-light at nanowatt power levels. This platform enables nanoscale imaging of Cooper pair dynamics and confined bosonic modes in low-dimensional systems, offering a new pathway toward quantum-limited spectroscopy and single-polariton detection. I will conclude by discussing future directions, including the integration of these techniques for exploring THz quantum optics, polaritonic circuitry, and strongly correlated quantum phases in complex materials.

Mengkun Liu (Ph.D. 2012 Boston University) is a professor at the Department of Physics and Astronomy of Stony Brook University (since Jan. 2015). His postdoc research was at UC San Diego from 2012-2014. His research interests include the physics of correlated electron systems, low-dimensional materials, infrared and terahertz nano-optics, and ultrafast time-domain spectroscopy. Prizes include the Moore EPI award (2023), SBU Discovery award finalist (2024), NSF career award (2021), and Seaborg Institute Research Fellowships at Los Alamos National Lab (2009, 2010).