A simple method for afterpulse probability measurement in high-speed single-photon detectors

• A simple and fast method for afterpulse probability measurement is proposed.
• Theory and implementation of the in-laser-period counting method are presented.
• The proposed method is verified on a 1.25-GHz single-photon detector.
• Comparisons among the proposed method and common methods are presented.
• Accuracy and error analyses are provided.

A simple statistical method is proposed for afterpulse probability measurement in high-speed single-photon detectors. The method is based on in-laser-period counting without the support of time-correlated information or delay adjustment, and is readily implemented with commercially available logic devices. We present comparisons among the proposed method and commonly used methods which use the time-correlated single-photon counter or the gated counter, based on a 1.25-GHz gated infrared single-photon detector. Results show that this in-laser-period counting method has similar accuracy to the commonly used methods with extra simplicity, robustness, and faster measuring speed.