Superconducting Nanowire Detector for Interstitial Null-Separation Time-Domain Diffuse Optical Spectroscopy

We demonstrate a novel realization of Interstitial fiber, broadband, Time Domain Diffuse Optical Spectroscopy (TD-DOS) in Null Source-Detector separation (NSDS) approach without temporal gating, by using a Superconducting Nanowire single photon detector (SNSPD) for acquisition. We test its feasibility by performing Monte Carlo simulations and comparing the absorption retrieval of the SNSPD with an ideal scenario and a standard Silicon Photomultiplier (SiPM). Consequently, as per the MEDPHOT protocol, we test experimentally, the absorption linearity of the system on tissue-equivalent liquid phantoms, and demonstrate the scattering-independent retrieval of the absorption spectrum of water using Intralipid phantoms in the wavelength range of 600-1100 nm.