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Resolving Higher-Order Pairs from a Single Pulse in High-Power SPDC

Phillip S. Blakey, Zacharie M. Léger, Trevor J. Stirling, Meng Lon Iu, Amr Saher Helmy

Published Jan 1, 2025• 0 citations
Publisher

Abstract

The non-local cancellation if dispersion is used to reduce accidental counts caused by multi-photon noise by 7.27 times in an SPDC Source. This makrs the first demonstration of a fully waveguided system enhancing a single photon detectors resolution to effectively reject uncorreltaed multi-photon noise from SPDC sources. This advancement has helps address a critical challenge in achieving higher pair rate SPDC sources without the associated degradation in state quality with applications for quantum sensing and communications.

DOI
10.1364/cleo_si.2025.ss115_7

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The non-local cancellation if dispersion is used to reduce accidental counts caused by multi-photon noise by 7.27 times in an SPDC Source. This makrs the first demonstration of a fully waveguided system enhancing a single photon detectors resolution to effectively reject uncorreltaed multi-photon noise from SPDC sources. This advancement has helps address a critical challenge in achieving higher pair rate SPDC sources without the associated degradation in state quality with applications for quantum sensing and communications.
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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.