Single Photon counting Modules – SPCM-AQRH

SPCM-AQRH is a self-contained module that detects single photons of light over the 400 nm to 1060 nm wavelength range - a range and sensitivity that often outperforms a photomultiplier tube. The SPCM-AQRH uses a unique silicon avalanche photodiode (SLiK®) with a circular active area that achieves a peak photon detection efficiency of more than 65 at 650 nm over a 180 µm diameter. The photodiode is both thermoelectrically cooled and temperature controlled, ensuring stabilized performance despite ambient temperature changes. Circuit improvements have reduced the overall power consumption. Count speeds exceeding 20 million counts per second (Mc/s) are achieved by the SPCM-AQRH-1X module (> 30 million counts per second on some models). There is a "dead time" of 35ns between pulses but other values can be set at the factory. As each photon is detected, a TTL pulse of 2.5 Volts (minimum) high into a 50 Ohm load and 15 ns wide is output at the rear BNC connector. The module is designed to give a linear performance at a case temperature between 5˚C and 40˚C. The SPCM is also available in a 4 channel array format, the SPCM-AQ4C. It is a module of 4 APDs with single power supply and 4 individual outputs. This series of photon counting modules are designed and built to be fully compliant with the European Union Directive 2002/95EEC - Restriction of the use of certain Hazardous Substances in electrical and electronic equipment (RoHS).