Based on a reach-through design, the SAP500 series avalanche photodiodes (APDs) feature excellent quantum efficiency, extremely low noise, and minimal dark current.
These APDs have an active area of D = 500 µm. They can either be operated in normal linear mode (VR < VBR) with an internal gain of 250 and higher or in “Geiger” mode. In Geiger mode the APDs are operated with a voltage larger than the breakdown voltage (VR > VBR). Single photons can be detected in this mode.
The new SAP500 series is ideally suited for applications in which the weakest light signals down to single photons can be quantified and detected in a time-resolved manner. This includes, for example, LIDAR systems, spectroscopy, fluorescence measurements, or photon counting.
Unlike photomultipliers (PMTs), they have the advantage of a small and compact design, the highest quantum efficiency, and very good time resolution. In addition, they are not affected by magnetic fields, are robust, have a long lifespan, work with low operating voltages, and are less expensive.
The APDs come in a hermetic TO-46 housing. They are also available with a thermoelectric cooler in a TO-37 housing or a two-stage TEC in a TO-8 housing.
