Quantitative determination of spatial resolution and linearity of position-sensitive LG-SiPMs at sub-millimeter scale via Ricean distribution fitting

Position-sensitive SiPMs are useful in all light detection applications requiring a small number of readout channels while preserving the information about the incoming light’s interaction position. Focusing on a 2 × 2 array of LG-SiPMs covering an area of $\sim 15.5\times 15.5{\mathrm{mm}}^2$ with just 6 readout channels, we proposed a quantitative method to evaluate the image reconstruction performance. The method is based on a statistical approach to assess the device’s precision (spatial resolution) and accuracy (linearity) in reconstructing the light spot center of gravity. This evaluation is achieved through a Rice probability distribution function fitting. We obtained an average sensor spatial resolution of $81\pm 3\mu m$ (standard deviation) with a corresponding accuracy of $231\pm 4\mu m$.