In situ electron-beam processing and cathodoluminescence microscopy for quantum nanophotonics

Non-linear manipulation of light at the nanoscale is increasingly important for quantum optics and photonics. Plasmonic media provide one important workbench for the manipulation of these nonlinearities.1 The design of plasmonic structures typically involves time-consuming, iterative, computer simulations, nanofabrication and characterization with large suites of independent tools. Hence, in-situ fabrication and characterization along with real time design optimization is an appealing option for the development of hybrid quantum nanophotonic devices. Here, we will describe emerging capabilities for in situ electron beam induced deposition (EBID) and cathodoluminescence (CL) microscopy in an environmental SEM. We outline our work writing and characterizing nanoplasmonic structures that exhibit well-defined field localization and multiple tunable resonances over a broad spectrum as part of the development of new high-efficiency nanophotonic nonlinear media. Developing deter- ministic high-quality single photon emitters is an equally important direction for photonic quantum information processing. Due to the sub-nanometer footprint of such emitters, optical methods are often insufficient for local characterization. We describe our efforts to create, manipulate and characterize color centers in 2D and bulk materials such as hBN. We discuss e-beam induced effects for localized defect creation and EBID based control of color centers to allow emission tuning. Cathodoluminescence lifetime and autocorrelation measurements are utilized for sub-diffraction-limited in-situ assessment of the single photon emission properties.