A Quantum Detector System For Hybrid Time-domain Diffuse Optics
ORAL
Abstract
Diffuse optics (DO) enables non-invasive monitoring of oximetry and flowmetry by combining time-domain near-infrared spectroscopy (TD-NIRS) [1] and time-domain diffuse correlation spectroscopy (TD-DCS) [2]. These methods require detectors with high near-infrared quantum efficiency (QE), excellent temporal resolution, and low dark count rate (DCR). We present a system based on superconducting nanowire single-photon detectors (SNSPDs) that fulfils these needs. In single-mode configuration at 785 and 1064 nm, QE exceeds 70%, DCR stays below 10 cps, and jitter remains under 40 ps.
To demonstrate suitability for TD-NIRS, we measured absorption spectra of tissue-mimicking liquid phantoms and successfully retrieved their optical properties thanks to the SNSPDs’ high dynamic range. For TD-DCS, we conducted an in-vivo occlusion experiment at 1050 nm on a healthy volunteer. A 3-minute baseline was followed by 3 minutes of cuff-induced blood flow blockage and subsequent release. The intensity autocorrelation functions clearly distinguished each stage and changes in decay rate reflected blood-flow variations. These results confirm that SNSPDs enable high-performance hybrid time-domain diffuse optics.
To demonstrate suitability for TD-NIRS, we measured absorption spectra of tissue-mimicking liquid phantoms and successfully retrieved their optical properties thanks to the SNSPDs’ high dynamic range. For TD-DCS, we conducted an in-vivo occlusion experiment at 1050 nm on a healthy volunteer. A 3-minute baseline was followed by 3 minutes of cuff-induced blood flow blockage and subsequent release. The intensity autocorrelation functions clearly distinguished each stage and changes in decay rate reflected blood-flow variations. These results confirm that SNSPDs enable high-performance hybrid time-domain diffuse optics.
*This project was partially funded by the fastMOT project, which is funded by the EU's HORIZON EUROPE programme under grant agreement number 101099291 and by the UK Research and Innovation (UKRI) under the UK government's Horizon Europe funding guarantee (grant number 10063660).
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Publication: [1] A. Pifferi et al. New frontiers in time-domain diffuse optics, a review (2016) Journal of biomedical optics, 21(9): 091310-091310.
[2] J. Sutin et al. Time-domain diffuse correlation spectroscopy (2016) Optica, 3(9): 1006-1013.
Presenters
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Katyayani Seal
- Single Quantum