Laser Components has launched a new silicon avalanche photodiode for linear and Geiger mode operation. Based on a reach-through design, the SAP500 series APDs) feature excellent quantum efficiency, extremely low noise, and minimal dark current.
These APDs have an active area of Ø500µm. They can either be operated in normal linear mode (VR < VBR) with an internal gain of 250 and higher, or in Geiger mode, in which the APDs are operated with a voltage larger than their breakdown voltage (VR > VBR). Single photons can be detected in this mode.
Unlike photomultiplier tubes (PMTs), the APDs offer 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. The SAP500 series is well suited to applications in which the weakest light signals (down to single photons) must be quantified and detected in a time-resolved manner. This includes, for example, LIDAR systems, spectroscopy, fluorescence measurements, or photon counting.