Experimental and extraction procedure for the electrical characterisation of silicon photomultiplier detectors

Silicon photomultipliers (SiPMs), owing to their low-level photon counting capabilities, have increased in popularity in the field of high energy astrophysics, particle physics and medical imaging. It is crucial to accurately characterise SiPMs so they can be optimised for a particular application such as the Compact High Energy Camera (CHEC-S) for Imaging Atmospheric Cherenkov Telescopes (IACT). Extraction techniques, applied to SiPMs, can quantify opto-electrical parameters such as gain, quenching resistance, junction, parasitic and grid capacitance, rise time constant and slow and fast fall time constants. Various authors have applied and compared different extraction techniques to SiPMs, usually based on the Laplace Transform in the s-domain of the equivalent circuit model. These techniques typically utilise the pulse tail, and therefore only parameterise the recharge phase of the pulse. We will improve upon existing methods by utilising the discharge phase of an SiPM pulse in our transfer function model. In this paper, we have also applied this method to present the electrical characterisation of a novel SiPM detector: Hamamatsu LVR3 S14520-6075. The paper also details a method by which an accurate, average pulse shape, uncontaminated by after-pulsing or dark noise, can be obtained. This is a prerequisite for our analysis method, which fits the pulse shape derived from the transfer function of the SiPM model to the experimental data.