The ability to discriminate the number of photons in a radiation field has a critical role in the implementation of quantum optical technologies. True photon-number-resolving detectors are rare and complex devices, while a quasi-photon-number-resolving detector (qPNRD) is a practical alternative for real-world applications. Our qPNRD is composed of a fibre demultiplexer and individual non-photon-number-resolving detectors. We perform quantum tomography on our qPNRD based on the positive operator-valued measure and extend the analysis using the Bayesian formalism to uncover how the measurement influences knowledge of the measured photon probability distribution.<p></p>
Funder Name
Department for Business, Energy and Industrial Strategy, UK Government; Horizon 2020 Framework ProgrammePreprint ID
111296Highlighter Commentary
The possibility of resolving the number of photons contained in an optical signal has triggered the development of novel quantum-enhanced technologies for metrology, imaging, sensing, and microscopy. In this preprint, researchers from the United Kingdom demonstrate an efficient quasi-photon-number-resolving detection system. The device makes use of fiber-based spatial demultiplexing in combination with an array of non-photon-number-resolving detectors. Although the detection system requires a complex numerical treatment---which includes a full quantum tomography and Bayesian statistical analysis---to extract the photon distribution of an optical signal, it represents an interesting approach to extracting the quantum statistics of light signals, especially because true photon-number-resolving detectors are not always available in the laboratory.
Roberto de J. León-Montiel
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México