High-resolution and large-stretch single photon-gated sampling of chaotic laser

Achieving high-fidelity acquisition and reconstruction of chaotic signals at a single-photon level remains a key challenge in secure communication and ultrasensitive sensing, primarily due to bandwidth and resolution limits of single-photon detectors (SPDs). In this work, we present an experimental method to recover high-bandwidth chaotic signals using low-bandwidth and high-sensitivity SPDs, which effectively mitigates the impacts of detector dead time and time jitter by shifting the signal spectrum into the SPD's response window and constructing a programmable gated sampling to time-stretch the signal. It achieves a maximum time stretching multiplication of 122 times, and the temporal resolution of SPD is improved by more than 24 times. For long-time high-precision sampling, a 16-channel FPGA-based time-to-digital conversion with a time resolution of 18.21 ps and a root mean square of 12.7 ps is self-developed to achieve high-efficiency single-photon signal acquisition by dynamically adjusting the sampling gate width. Single-gated time-stretch sampling of distorted single-photon signals achieves 95% fidelity experimentally. In time-interleaved gating sampling, parallel acquisition shortens the sampling time compared to single-gated sampling and captures transient variations of chaotic signals with 94% fidelity. Our method achieves an expansion of the effective sampling rate by over 100 times while maintaining the single-photon level sensitivity, providing an effective solution for ultrafast single-photon detection.