Speaker
Description
Silicon Photomultipliers (SiPMs) offer exceptional photon detection sensitivity, but face challenges in maintaining linearity across their operational range. At low light levels, the primary effect is the non-linearity of gain resulting from the voltage dependence of pixel capacitance. At high light intensities, the finite pixel count leads to non-linear response, limiting the dynamic range.
A key challenge in correcting non-linearity is the traditional requirement for a reference linear light source to determine the non-linear response correction. To overcome this limitation, the so called "single-step method", originally developed for PMT calibration, can be applied. This technique is based on the difference in responses to two light sources, eliminating the need for an absolute reference. This approach effectively corrects SiPM non-linearity, significantly extending the usable dynamic range.
The talk will present and discuss the systematic studies conducted in the laboratory, where the response of various SiPMs with different pixel dimensions, operated at different temperatures, and overvoltages were measured and corrected using this method. Results highlight that the response function remains stable across an overvoltage range of 2-4 V and shows only mild temperature dependence over a 40 K range. Furthermore, linearity within 1% can be achieved by applying a single correction function within ± 5 K and ± 2 V of the original measurement conditions.
