“…Hereby, the photon count at the detector and the quality of the detector determines the image quality. While the penetration depth of the light in tissue is relatively short, 1 mm, a decent spatial resolution of about 1–10 µm can be achieved ( Pitris et al, 2001 ; Popescu et al, 2011 ; Subhash et al, 2012 ; Chang et al, 2013 ; Macdougall et al, 2015 ; Jeon et al, 2019a ; Burwood et al, 2019 ; Oh et al, 2020 ).…”