SEQUME (2021-2024)

This project further develops the protocols and instrumentation required for measurements at the single-photon level, including sub-shot noise measurements, quantum imaging, sub-diffraction imaging, and quantum illumination. In addition, novel methods for the fabrication of single-photon sources have been developed and optimized for such parameters as purity and brightness.

The goal of this project is to establish a metrology infrastructure for have and calibration of single-photon sources and detectors. For this, the consortium has developed new single-photon sources and entangled-photon sources for traceable measurements and specify their performance parameters. New validation methods have been produced to optimize sources for have highest purity characterization (g⁽²⁾(t = 0) close to 0), brightness (photon rate > 5 × 10⁶ photons per second) and indistinguishability (Hong-Ou-Mandel visibility > 95 %). The capabilities developed in the evolving metrology infrastructure is being used for the traceable characterization of entangled-photon and single-photon sources, amplifiers, and standardized quantum-optical setups.

Within this project, MRI of Aalto University utilized a liquid-nitrogen cooled Predictable Quantum Efficient Detector (PQED) for calibrations of single-photon detectors with photon flux down to 0.5 million photons per second. Calibration measurements were made for a single-photon detector of National Institute of Chemical Physics and Biophysics (KBFI) [1].

Publications

1. Korpusenko M., Sildoja M., Manoocheri F., and Ikonen E., Measurements of Low Optical Power with Cryostat-Based Predictable Quantum Efficient Detector at Liquid Nitrogen Temperature (submitted).