Event Date
Photon Avalanching Nanoparticles: Extreme Nonlinearity for Sub-Diffraction Imaging, Sensing, and Optical Computing.
Lanthanide-doped nanomaterials exhibit nonlinear photophysical dynamics that give rise to photon upconversion, in which low-energy light is converted to photons with higher energies. I will discuss the discovery and application of a new class of upconverting nanocrystals, known as photon avalanching nanoparticles (ANPs), that exhibit optical responses that are more nonlinear than those of 30-photon processes. I will demonstrate how such giant nonlinearities enable two distinct modes of sub-diffraction imaging: one that achieves < 70 nm resolution using standard confocal microscopy, and another that achieves < 1 Å localization accuracies using stochastic localization microscopy. I will describe the use of computational modeling and high-throughput robotic synthesis to expand the library of ANPs. For example, we developed a class of ANPs based on perovskite-like potassium lead halide hosts with low phonon energies. These neodymium-doped ANPs can achieve >200th-order nonlinearities and exhibit luminescence hysteresis characteristic of intrinsic optical bistability. Finally, I will discuss how these ANP properties can be leveraged for nanoscale sensing and as optical memory and transistors.