Source: XP Power
When it comes to low intensity light detection, performance requirements often lead to selecting devices with greater sensitivity than common photodiodes or even charge coupled devices (CCDs). Specialized detectors such as avalanche photodiodes (APDs), photomultiplier tubes (PMTs) and microchannel plates (MCPs) are often employed for these more precise applications. High sensitivity devices bring with them a set of electronic design considerations needed to maximize the performance
potential of the system.
Applications requiring sensitive light detection include spectroscopy, radiation detection, night vision, laser rangefinders, long-range fiber-optic telecommunication, blood analyzers, positron emission tomography and particle physics, to name but a few. These devices convert incoming light into an electronic signal via the photoelectric effect, whereby electrons are ejected when photons strike a photosensitive surface. The photosensitive surface is frequently held at high voltage potential, usually from around 100V up to about 6000V depending on the device, and commonly at negative voltage potential.