Performance of a visible light photon counting imaging detector for weak light intensities

In this study, a visible light photon-counting imaging detector was developed for weak light intensities, such as biofluorescence and photon-counting 3D imaging radars. The proposed visible light photon-counting imaging detector was based on a semitransparent S25 photocathode able of responding to visible light or even near-infrared wavelengths. The detector adopted image charge readout mode through high-resistance Ge layer receiver of electron cloud from the microchannel plate. The performance of the as-obtained visible light photon-counting imaging detector was tested in existing readout electronics and newly designed position-sensitive anodes. The quantum efficiency of the as-prepared detector reached 13.4% (@532 nm) with spatial resolution better than 100 μm. Preliminary imaging results of real objects with commercial lens and detector were also obtained and applied to ultra-weak light detection. In sum, these results look promising for future applications in photon-counting radars and biofluorescence imaging.