Single-photon avalanche diode

Patent Pending A single-photon avalanche diode (SPAD) (also known as a Geiger-mode APD or G-APD) is a solid-state photodetector in which a photo-generated carrier can trigger an avalanche current due to the impact ionization mechanism. This device is able to detect low intensity signals (down to the single photon) and to signal the arrival times of the photons with a jitter of a few tens of picoseconds.