Advances in Quantum Metrology with Dielectrically Structured Single Photon Sources Based on Molecules

In the realm of fundamental quantum science and technologies, non-classical states of light, such as single-photon Fock states, are widely studied. However, current standards and metrological procedures are not optimized for low light levels. Progress in this crucial scientific domain depends on innovative metrology approaches, utilizing reliable devices based on quantum effects. A new generation of molecule-based single-photon sources is presented, combining their integration in a polymeric micro-lens with pulsed excitation schemes, thereby realizing suitable resources in quantum radiometry. The strategy enhances the efficiency of generated single photon pulses and improves stability, providing a portable source at 784.7 nm that maintains consistent performance even through a cooling and heating cycle. The calibration of a single-photon avalanche detector is demonstrated using light sources with different photon statistics, and the advantages of the single-molecule device are discussed. A relative uncertainty on the intrinsic detection efficiency well below 1% is attained, representing a new benchmark in the field. Exploiting the integration in polymeric micro-lenses, a new generation of molecule-based single-photon sources for quantum radiometry is presented. The emitters exhibit enhanced efficiency and improved stability, as their optical properties result largely unaffected by a successive cooling-heating cycle. The calibration of a single-photon avalanche detector is demonstrated and the advantages of using the single-molecule device are discussed. image