Technical Article: Low-Light Detection With Silicon Photomultipliers

By DR. CARL JACKSON

Detecting low levels of light is of critical importance for many applications. Being able to determine the correct detector solution for a given application is sometimes a challenging task as there are numerous solutions on the market today. Low-light detectors and low-light detector arrays enable a wide range of applications, including measurement and analytical systems, industrial inspection, nuclear medicine (particularly positron emission tomography, or PET), radiation detection, homeland security, and ranging applications such as LIDAR (light detection and ranging).

These markets rely on the ability of the sensor to detect light levels that range from one to millions of photons per second, or per pulse. Signals can be single pulses of light or continuously varying optical flux, depending on the application. The differences in the types of optical input and the required output from the detector require that the detector solution be flexible to allow integration into a variety of systems. System requirements are increasing in complexity, shrinking in form factor, increasing in reliability, and there is always a desire to decrease system cost to increase market penetration. Traditionally, the low-light detector market has been served by either the vacuum tube photomultiplier tube (PMT) or the avalanche photodiode (APD).