A Multi‐Dimensional Cathodoluminescence Detector With 3D Printed Micro‐Optics on a Fiber

ABSTRACT Cathodoluminescence, i.e., the radiation caused by the interaction of high‐energy electron beams with matter, has gained a major interest in the analysis of minerals, semiconductors, and plasmonic resonances in nanoparticles. This radiation can either be coherent or incoherent, depending on the underlying interaction mechanism of electrons with nanostructured matter. Thanks to their high spatial resolution and large spectral excitation bandwidth, the evanescent near‐field of a moving electron in a scanning electron microscope is used to probe locally photonic modes at the nanoscale, e.g., exciton or plasmon polaritons. The properties of these excitations can be analyzed through both spectral and temporal statistics of the emitted light. Here, we report on the technical design and implementation of a novel fiber‐based cathodoluminescence detector for a scanning electron microscope. Moreover, we present first characterization measurements to prove the ability for raster scanning the cathodoluminescence emission using optical fibers with 3D printed micro‐optics. The functionality and flexibility of this fiber‐based detector is highlighted by resolving the spatial far‐field distribution of the excited light, as well as cathodoluminescence spectroscopy and time‐correlated single photon counting. Our findings pave the way for a better understanding of the characteristic of the light emitted from electron beams interacting with nanostructures and 2D materials.