Photon number resolving SiPM detector with 1 GHz count rate

We demonstrate 1 GHz count rate photon detection with photon number resolution by using a multi-pixel photon counter (MPPC) and performing baseline correction. A bare MPPC chip mounted on a high-frequency circuit board is employed to increase response speed. The photon number resolving capability is investigated at high repetition rates. This capability remains at a repetition rate of 1 GHz and at rates as high as an average of 2.6 photons detected per optical pulse. The photon detection efficiencies are 16% at λ = 450 nm and 4.5% at λ = 775 nm with a dark count rate of 270 kcps and an afterpulse probability of 0.007.