Photon Counting is an ultra-sensitive detection technique that resolves and counts individual photons rather than measuring average optical power, enabling extremely low-light measurements that conventional detectors cannot perform. It is used in quantum optics, fluorescence lifetime imaging, LIDAR, single-photon communication, and astrophysics. Photon counting typically requires detectors with very high gain and low noise, such as single-photon avalanche diodes (SPADs). GPD’s expertise in APD design and low-noise detector fabrication supports customers developing photon-counting systems for research and advanced sensing applications.
Choosing a photodetector isn’t just a spec-matching exercise. The wrong choice drives redesign cycles, calibration overhead, and supplier risk that never appear on a datasheet. Here’s how to evaluate detectors the way your product’s lifecycle actually demands.