Statistical Study of Intrinsic Parasitics in an SPAD-Based Integrated Fiber Optical Receiver

Recently, a fully integrated optical fiber receiver was reported based on single-photon avalanche diode detectors to reduce the sensitivity gap to the quantum limit. This was realized through an array of four detectors to overcome the parasitic effects dominated by afterpulsing which prevent a single detector from providing an acceptable performance to serve as an optical receiver. However, the array structure imposes an extra effect called “crosstalk,” which needs to be accurately characterized. Thanks to the memoryless nature of dark noise statistics, we present an effective method to investigate the intrinsic parasitic effects of the array based on an all-at-once dark noise measurement. The corresponding detection probabilities and delays versus excess bias voltage are obtained for different parasitics at all detectors. The results are used to model crosstalk and estimate the error probabilities required for bit error ratio analysis and structure optimization. The accuracy of the estimations is verified by experimental data.