Fast and compact multichannel photon coincidence unit for quantum information processing

We present a fast and compact multichannel coincidence unit to count all possible single and coincidence detection events in an experiment with eight single-photon detectors at once. Using high-speed electronics and a microcontroller, this device is able to process up to 800 000 events/s. The coincidence window can be tuned within a range of 4-12 ns. The device can be easily scaled to any number of input channels and is thus ideally suited for efficient multiphoton quantum information processing. (c) 2005 American Institute of Physics.