  Color centers in diamond play a central role in the development of quantum
photonic technologies, and their importance is only expected to grow in the
near future. For many quantum applications, high collection efficiency from
individual emitters is required, but the refractive index mismatch between
diamond and air limits the optimal collection efficiency with conventional
diamond device geometries. While different out-coupling methods with near-unity
efficiency exist, many have yet to be realized due to current limitations in
nanofabrication methods, especially for mechanically hard materials like
diamond. Here, we leverage electron-beam-induced etching to modify Sn-implanted
diamond quantum microchiplets containing integrated waveguides with width and
thickness of 280 nm and 200 nm, respectively. This approach allows for
simultaneous high-resolution imaging and modification of the host matrix with
an open geometry and direct writing. When coupled with the cathodoluminescence
signal generated from the electron-emitter interactions, we can monitor the
enhancement of the quantum emitters in real-time with nanoscale spatial
resolution. The operando measurement and manipulation of single photon emitters
demonstrated here provides a new foundation for the control of emitter-cavity
interactions in integrated quantum photonics.
