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This content will become publicly available on December 1, 2025

Title: Effects of multi-photon states in the calibration of single-photon detectors based on a portable bi-photon source
Single-photon detectors (SPDs) are ubiquitous in many protocols for quantum imaging, sensing, and communications. Many of these protocols critically depend on the precise knowledge of their detection efficiency. A method for the calibration of SPDs based on sources of quantum-correlated photon pairs uses single-photon detection to generate heralded single photons, which can be used as a standard of radiation at the single-photon level. These heralded photons then allow for precise calibration of SPDs in absolute terms. In this work, we investigate the absolute calibration of avalanche photodiodes based on a portable, commercial bi-photon source, and investigate the effects of multi-photon events from the spontaneous parametric down conversion (SPDC) process in these sources. We show that the multi-photon character of the bi-photon source, together with system losses, has a significant impact on the achievable accuracy for the calibration of SPDs. However, modeling the expected photon counting statistics from the squeezed vacuum in the SPDC process allows for accurate estimation of the efficiency of SPDs, assuming that the system losses are known. This study provides essential information for the design and optimization of portable bi-photon sources for their application in on-site calibration of SPDs with high accuracy, without requiring any other reference standard.  more » « less
Award ID(s):
2210447 2444171
PAR ID:
10624963
Author(s) / Creator(s):
; ;
Publisher / Repository:
AVS Quantum Science, AIP Publishing Group
Date Published:
Journal Name:
AVS Quantum Science
Volume:
6
Issue:
4
ISSN:
2639-0213
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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