Transmission electron microscopy is an excellent experimental tool to study the interaction of free electrons with nanoscale light fields. However, up to now, applying electron microscopy to quantum optical investigations was hampered by the lack of experimental platforms that allow for a strong coupling between fast electrons and high-quality resonators. Here, as a first step, we demonstrate the broad-band excitation of optical whispering-gallery modes in silica microresonators by fast electrons. In the emitted coherent cathodoluminescence spectrum, a comb of equidistant peaks is observed, resulting in cavity quality factors larger than 700. These results enable the study of quantum optical phenomena in electron microscopy with potential applications in quantum electron-light metrology.

中文翻译：

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快速电子到高 Q 回音画廊模式谐振器的宽带耦合

透射电子显微镜是研究自由电子与纳米级光场相互作用的极好实验工具。然而，到目前为止，由于缺乏允许快速电子和高质量谐振器之间强耦合的实验平台，将电子显微镜应用于量子光学研究受到阻碍。在这里，作为第一步，我们展示了快速电子对二氧化硅微谐振器中光学回音壁模式的宽带激发。在发射的相干阴极发光光谱中，观察到等距峰的梳状，导致腔质量因子大于 700。这些结果使研究电子显微镜中的量子光学现象成为可能，并在量子电子光计量学中具有潜在应用。