Quantum optical properties of solid-state defects using stage scanning confocal microscopy.

Solid-state quantum emitters (QEs) at room temperature are central to emerging technologies in quantum computing, communication, and sensing. These atomic-scale defects require high-resolution spatial and spectral characterisation to study their photophysical behaviour. To address this, we developed a stage-scanning confocal microscopy system optimised for nanoscale mapping and single photon level investigations of QEs in diverse host materials, fully automated and controlled via custom LabVIEW software. The system features high-precision three-axis translation stages with nanometre resolution, enabling accurate spatial scanning. A high numerical aperture (NA) objective lens ensures diffraction-limited optical resolution, while integrated photon-counting modules allow for sensitive detection of photoluminescence signals. The platform supports various spectroscopic measurements, including frequency-resolved and time-resolved photoluminescence. The system incorporates a Hanbury Brown and Twiss (HBT) interferometer for second-order temporal autocorrelation measurements to verify single photon emission. Designed for versatility, the system can accommodate a broad range of QE materials, including organic dye molecules, perovskites, and inorganic semiconductors. Furthermore, the setup enables the study of emission engineering through the manipulation of the local density of optical states, supported by the ability to collect large-scale statistical datasets. Overall, the flexibility and robustness of the platform make it ideal for quantum photonic, supporting fundamental studies and practical device development.