Single-photon avalanche photodiode (SPAD) and silicon photomultiplier (SiPM) are related photodetector technologies. Among several similarities, one stands out: each is able to produce a measurable output current in response to a single photon. Only one other point photodetector, a photomultiplier tube (PMT), is capable of such detection. The extraordinary light sensitivity of these three photodetectors is due to their very high (~106) intrinsic gain. Compared to a PMT, SiPM and SPAD are newer technologies, only now being adopted in those applications involving ultra-low light levels. Both can offer a number of advantages over a PMT, without sacrificing performance. Some of the advantages are a smaller size, better mechanical and electrical durability, lower power consumption, and immunity to magnetic fields and ambient light. Despite these advantages, SiPM and SPAD are the less known and understood photodetectors compared to a PMT. The purpose of this webinar is to create a greater awareness of SiPMs and SPADs among engineers, researchers, and scientists in varied technical fields but involved in low-light level photodetection.
Topics of presentation:
- Discussion of the principles of operation of a SPAD and SiPM, followed by a brief comparison of both photodetectors to a PMT.
- Discussion of optoelectronic characteristics of modern SiPMs and SPADs, whose understanding is essential in the selection of the optimal photodetector.
- At the core of any photodetection system is a photodetector together with the front-end electronics; thus, the webinar reviews the most common detection electronic circuits.