Periodic Reporting for period 2 - fastMOT (Fast gated superconducting nanowire camera for multi-functional optical tomograph)
Período documentado: 2024-04-01 hasta 2025-09-30
The novel sensor is based on superconducting nanowire single-photon detectors, which have been shown to be ultra-fast and highly efficient. However, the active area and number of pixels have so far been limited to micrometre diameters and tens of pixels. The fastMOT consortium now aims at developing new techniques to overcome this limit and scale to 10,000 pixels and millimetre diameter. In addition, new strategies for performing time domain near infrared spectroscopy (TD-NIRS) and time domain speckle contrast optical spectroscopy (TD-SCOS) will be developed to optimally use this new light sensor with Monte-Carlo simulations.
The benefits of this new technology include:
* Higher accuracy of non-invasive diagnosis: The proposed MOT has the potential to significantly improve the accuracy of non-invasive diagnosis and will make it possible to monitor body functions such as oxygenation, haemodynamics or perfusion.
* 100x improvement of signal-to-noise ratio: Implemented in the new Multifunctional Optical Tomograph, the light sensor will achieve a 100x improvement of signal-to-noise ratio compared to using existing light sensors.
* Major impact on numerous sectors: Not only will the new sensing technology improve microscopy and imaging performance, but it will also enable ground breaking applications that will lead to new insights and a major economic boost.
In addition, we set up a laboratory working station at Politecnico Milano that combines Single Quantum’s superconducting nanowire single-photon detectors (SNSPDs) with state-of-the-art laser systems to allow the exploration of the experimental parameters for functional diffuse optical imaging deep into the brain, in particular the combination of time-domain Near Infrared spectroscopy (TD-NIRS) and time-domain speckle correlation spectroscopy (TD-SCOS). We achieved some promising initial results on the experimental setup that will allow to define the next steps in the project.
In the second reporting period, we exploited the laboratory working station with single-pixel SNSPDs for time-domain Near-infrared spectroscopy and speckle correlation spectroscopy to find a good set of experimental parameters (laser wavelength and pulse duration) for the experiments. This will be the stepping stone to develop the tomographic working station. We also scaled up the number of pixels in an SNSPD array with independently addressed pixels to 100 total channels in one single system. This device will be use to benchmark the complete solution of hybrid TD-NIRS and TD-SCOS in a tomographic approach.
In this second period for the project, on the Single Quantum’s superconducting nanowire single-photon detectors (SNSPDs) side, we successfully duplicated the total number of independently addressed SNSPDs inside a single cryostat, to reach 100 channels. The efforts at TU Delft showed an experimental proof-of-principle of optical gating of an SNSPD, delivering sub-nanosecond gating speeds. On the development of the modeling for light propagation in the brain, we created a software virtual instrument that integrates Monte Carlo light transport with realistic source and multi-pixel SNSPD detector models. This software allows us to evaluate system performance and guide our experimental efforts. We experimentally tested the suitability of different laser sources for the experiments and identified the most promising candidate for the optical configuration for the homograph and performed liquid phantom tests demonstrating system stability, quality and sensitivity. These results were presented in several scientific dissemination channels such as conferences and journal publications.