Accessing photon bunching with photon number resolving multi-pixel detector

Recently, a compact and cost-efficient photon-number resolving detectors became commercially available with the introduction of a Multi Pixel Photon Counter (MPPC). In MPPC several hundred of avalanche photodiodes (APD) are embedded in a chip with their outputs connected into a summation circuit. The amplitude of MPPC output is proportional to the number of simultaneously firing APDs, which, in an ideal case, is equivalent to the number of incident photons. The most crucial limitation of MPPC is the crosstalk between APDs. The crosstalk manifests itself when a photon re-emitted during the avalanche in a given APD triggers a simultaneous “fake” avalanche in neighbor APD. Due to the crosstalk, an accurate reconstruction of photon statistics of the impinging light becomes quite complicated.