Shaping light-matter interactions for free-electron radiation and photonic computing

Abstract

Nanophotonics has become over the past decades a paramount technology, enabling, among other things, the design of novel light sources, detectors, and devices controlling the polarization, spectral, and angular distribution of light. A landmark of nanophotonics is the design of nanostructured materials (metasurfaces, photonic crystals, single resonators, etc.) to tailor the interaction of light with matter, either by shaping light propagation at the nanoscale, or by controlling emission from atoms and molecules. In this thesis, we propose two avenues in which nanophotonics can be leveraged to enhance light-matter interactions with applications in enhancing free-electron radiation and implementing Monte Carlo sampling algorithms in photonic circuits. We present a framework to model, tailor, and enhance radiation from free electrons and other high-energy particles interacting with nanophotonic structures. We then describe the building of a featured experimental setup to record spectrally-resolved light emission from free electrons interacting with nanophotonic structures. We utilize this setup to demonstrate nanophotonic enhancement of coherent and incoherent cathodoluminescence. We also present methods to realize fast and efficient sampling of Gibbs distributions of arbitrary Ising models with recurrent photonic circuits. Those methods are experimentally demonstrated in a photonic integrated circuit on small-scale Ising models. Lastly, we propose future research developments based on those findings and possible research avenues at their intersection.