Key Takeaways & Executive Findings
- •• Proposed a retiming scheme using coincidence signals synchronized with sinusoidal gating to suppress detection signal jitter in high-speed SPDs. • Identified key contributors to rising-edge jitter: optical pulse width, avalanche generation, signal extraction, and pulse discrimination. • Achieved significant reduction in after-pulse probability from 10.7% to 0.72% in a 1.25 GHz InGaAs/InP SPD. • Method is simple to implement and avoids direct interference with detector operation, enhancing QKD system performance.
Abstract
Quantum key distribution (QKD) achieves information-theoretic security based on quantum mechanics principles, where single-photon detectors (SPDs) serve as critical components. This study focuses on the sinusoidal gated SPDs widely used in high-speed QKD systems. We investigate the mechanisms underlying the rising-edge jitter in detection signals, identifying contributions from factors such as the temporal width of injected optical pulses, avalanche generation processes, avalanche signal extraction, and pulse discrimination. To address the issue of excessive jitter-induced bit errors, we propose a retiming scheme that utilizes coincidence signals synchronized with the sinusoidal gating signal. This approach effectively suppresses detection signal jitter and reduces the after-pulse probability of the detector. Experimental validation using a high-precision time-to-digital converter (TDC) demonstrates a significant reduction in the rising-edge jitter distribution after applying the suppression scheme. The proposed method features clear principles and straightforward engineering implementation, avoiding direct interference with the detector's operational processes. The designed high-speed sinusoidal gated InGaAs/InP SPD operates at 1.25 GHz, achieving a remarkable reduction in after-pulse probability from 10.7% (without jitter suppression) to 0.72%, thereby enhancing the overall performance of QKD systems.
1. Introduction
Single-photon detectors (SPDs) represent ultra-sensitive devices capable of detecting light at the quantum limit, enabling the capture and conversion of single photon energies. These detectors are not only critical components in quantum key distribution (QKD) systems but also play essential roles in quantum metrology, lidar, fluorescence lifetime imaging, and space exploration.
In practical QKD systems, single-photon avalanche diodes (SPADs) are predominantly utilized for photon detection. However, SPADs inherently exhibit high noise levels, necessitating noise suppression techniques such as active gated quenching or passive quenching via ne...
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Lianjun Jiang, Dongdong Li, Dawei Li, Yuqiang Fang, Ming Liu, Wei Jiang, Zhilin Xie, Guoqing Liu, Rui Ma, Yukang Zhao, Jian Sun, Lei Chang, Lin Yu, Shibiao Tang (2025). Jitter suppression scheme for detection pulses in high-speed sinusoidal gated single-photon detectors. SinoTechIntel Verified Research. https://doi.org/10.1088/1674-4926/25030031
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Frequently Asked Questions
What is the main contribution of this paper?
The paper proposes a retiming scheme using coincidence signals synchronized with the sinusoidal gating signal to suppress detection signal jitter in high-speed sinusoidal gated single-photon detectors, significantly reducing after-pulse probability and improving QKD system performance.
How does the proposed jitter suppression scheme work?
The scheme utilizes coincidence signals synchronized with the sinusoidal gating signal to retime the detection pulses, effectively reducing the rising-edge jitter distribution without directly interfering with the detector's operational processes.
What are the key factors contributing to rising-edge jitter in detection signals?
The key factors include the temporal width of injected optical pulses, avalanche generation processes, avalanche signal extraction, and pulse discrimination.
What experimental results were achieved with the proposed scheme?
Using a high-precision time-to-digital converter, the scheme demonstrated a significant reduction in rising-edge jitter distribution. In a 1.25 GHz InGaAs/InP SPD, the after-pulse probability was reduced from 10.7% to 0.72%.
What is the significance of this work for quantum key distribution?
By suppressing jitter and reducing after-pulse probability, the proposed method enhances the overall performance of QKD systems, which rely on single-photon detectors for secure communication.
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