Traceable characterisation of fibre-coupled single-photon detectors

TY - JOUR

T1 - Traceable characterisation of fibre-coupled single-photon detectors

AU - Arabskyj, Luke

AU - Dolan, Philip R.

AU - Parke, Adam L.

AU - Santana, Ted S.

AU - Hall, Simon R.G.

AU - Porrovecchio, Geiland

AU - Smid, Marek

AU - Lucamarini, Marco

AU - Chunnilall, Christopher J.

N1 - © 2024 The Author(s). Published on behalf of BIPM by IOP Publishing Ltd

PY - 2024/9/9

Y1 - 2024/9/9

N2 - The detection of single photons plays an essential role in advancing single-photon science and technologies. Yet, within the visible/near-infrared spectral region, accurate fibre-based optical power measurements at the few-photon level are not yet well-established. In this study, we report on a fibre-based setup, enabling traceable optical power measurements at the few-photon level in this spectral region. The setup was used to calibrate the detection efficiency (DE) of four single-photon avalanche diode (SPAD) detectors. The relative standard uncertainties on the mean DE values obtained from repeat fibre-to-detector couplings ranged from 0.67% to 0.81% (k = 2). However, the relative standard deviation of DE values, which ranged from 1.38% to 3.20% (k = 2), poses a challenge for the metrology of these devices and applications that require high accuracy and repeatability. We investigated the source of these variations by spatially mapping the response of a detector’s fibre connector port, using a focused free-space beam, allowing us to estimate the detector’s spatial non-uniformity. In addition, we realise a novel calibration approach for fibre-coupled SPADs in a free-space configuration, enabling a direct comparison between the fibre-based setup and the National Physical Laboratory’s established free-space facility using a single SPAD. Finally, we investigated alternative coupling methods, testing the repeatability of different fibre-to-fibre connectors in addition to direct fibre-to-detector couplings: SPADs from three manufacturers were tested, with both single-mode and multi-mode fibre.

AB - The detection of single photons plays an essential role in advancing single-photon science and technologies. Yet, within the visible/near-infrared spectral region, accurate fibre-based optical power measurements at the few-photon level are not yet well-established. In this study, we report on a fibre-based setup, enabling traceable optical power measurements at the few-photon level in this spectral region. The setup was used to calibrate the detection efficiency (DE) of four single-photon avalanche diode (SPAD) detectors. The relative standard uncertainties on the mean DE values obtained from repeat fibre-to-detector couplings ranged from 0.67% to 0.81% (k = 2). However, the relative standard deviation of DE values, which ranged from 1.38% to 3.20% (k = 2), poses a challenge for the metrology of these devices and applications that require high accuracy and repeatability. We investigated the source of these variations by spatially mapping the response of a detector’s fibre connector port, using a focused free-space beam, allowing us to estimate the detector’s spatial non-uniformity. In addition, we realise a novel calibration approach for fibre-coupled SPADs in a free-space configuration, enabling a direct comparison between the fibre-based setup and the National Physical Laboratory’s established free-space facility using a single SPAD. Finally, we investigated alternative coupling methods, testing the repeatability of different fibre-to-fibre connectors in addition to direct fibre-to-detector couplings: SPADs from three manufacturers were tested, with both single-mode and multi-mode fibre.

KW - detection efficiency

KW - detector calibration

KW - fibre-coupled

KW - repeatability

KW - SI traceable

KW - Si-SPAD

KW - single-photon avalanche diode

UR - http://www.scopus.com/inward/record.url?scp=85203858334&partnerID=8YFLogxK

U2 - 10.1088/1681-7575/ad70bc

DO - 10.1088/1681-7575/ad70bc

M3 - Article

AN - SCOPUS:85203858334

SN - 0026-1394

VL - 61

JO - Metrologia

JF - Metrologia

IS - 5

M1 - 055008

ER -