Excelitas offers Avalanche Photodiodes (APDs) on both Silicon (Si) and InGaAs materials. Si APDs cover the spectral range of 400 nm to 1100 nm and the InGaAs APDs cover 950 nm to 1550 nm. An Avalanche Photodiode (APD) provides higher sensitivity than a standard photodiode and is for extreme low-level light (LLL) detection and photon counting.
The use of APDs instead of PIN photodetectors will result in improved sensitivity in many applications. In general, APDs are useful in applications where the noise of the amplifier is high, for example, much higher than the noise in the PIN photodetector.