Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

IEEE Transactions on Applied Superconductivity

High-Reliability Nanosecond-Level Gating Filtering Circuit for High-Performance SSPD

Junjie Wu, Huixiang Liu, Guangzhao Xu, Changmin Li, Chaolin Lv, Xuxiao Wan, Jia Huang, Hao Li, Lixing You

Published Nov 7, 2025• 0 citations
Publisher

Abstract

Superconducting strip single-photon detectors (SSPDs) have demonstrated superior performance in quantum key distribution, high-speed optical communication and et al. However, these applications are constrained by latching effects, dark count rates, and speed of detection, and the rapid detection of single photon events in the target time range requires proper readout means to control. This study presents a nanosecond-level gating filtering circuit with high reliability based on direct current biasing, enabling window-selective photon detection through time-controlled bias current modulation while maintaining superconductivity with reduced current during non-gate intervals. Experimental results show that the proposed scheme achieves a 3 ns–500 ns adjustable gating window and preserving high system detection efficiency and low timing jitter under specific windows. Compared to conventional approaches, the dark count rate is reduced by nearly one orders of magnitude, and the photon dynamic range is significantly expanded.

DOI
10.1109/tasc.2025.3630144

Related papers

Nanosecond gating of superconducting nanowire single-photon detectors using cryogenic bias circuitry

Thomas Hummel, Alex Widhalm, Jan Philipp Höpker +7 more

Superconducting nanowire single-photon detectors (SNSPDs) show near unity efficiency, low dark count rate, and short recovery time. Combining these characteristics with temporal control of SNSPDs broadens their applications as in active de-latching for higher dynamic range counting or temporal filtering for pump-probe spectroscopy or LiDAR. To that end, we demonstrate active gating of an SNSPD with a minimum off-to-on rise time of 2.4 ns and a total gate length of 5.0 ns. We show how the rise time depends on the inductance of the detector in combination with the control electronics. The gate window is demonstrated to be fully and freely, electrically tunable up to 500 ns at a repetition rate of 1.0 MHz, as well as ungated, free-running operation. Control electronics to generate the gating are mounted on the 2.3 K stage of a closed-cycle sorption cryostat, while the detector is operated on the cold stage at 0.8 K. We show that the efficiency and timing jitter of the detector is not altered during the on-time of the gating window. We exploit gated operation to demonstrate a method to increase in the photon counting dynamic range by a factor 11.2, as well as temporal filtering of a strong pump in an emulated pump-probe experiment.

arXiv:2210.14841•Optics Express•Nov 18, 2022•13 citations

Practical High-Efficiency SNSPD Balanced High Speed and Low Jitter on Filter Circuit

Changmin Li, Guangzhao Xu, Xingyu Zhang +7 more

Superconducting nanowire single-photon detectors (SNSPDs) are integral to the fields of quantum information and quantum communication, offering high efficiency, low dark count rate, high count rate, and minimal timing jitter. However, a common challenge with SNSPDs is their propensity for latching and nonlinear count rate increase under high incident photon fluxes due to the traditional external readout circuitry. This issue is primarily caused by large dynamic inductance and the ac-coupled effects of the bias and amplifier capacitors. In this study, we carefully selected a commercial SNSPD with an efficiency of over 95%. To address the aforementioned challenges, we implemented a resistor–inductor-type filter structure, which is directly coupled to a low-temperature amplifier, and their operating temperature is 40 K. Experimental results revealed that the enhanced SNSPD readout circuit achieves a count rate that is approximately 3.5 times greater than that of the traditional circuit. Moreover, the timing jitter of the SNSPD was optimized, decreasing by approximately 3.6 times under high incident photon fluxes. These performance enhancements could significantly improve high-speed optical communication and quantum precision measurement.

IEEE Transactions on Applied Superconductivity•Jul 15, 2024•3 citations

Superconducting nanowire single photon detector under AC-bias with self-differential readout

Luyao Ma, Xing-Yu Zhang, Zhi-Yun Shu +4 more

Superconducting nanowire single photon detector (SNSPD) has been widely used in many fields such as quantum computing, quantum key distribution and laser radar, due to its high detection efficiency, low dark count rate, high counting rate, and low timing jitter. In most cases, the SNSPD works under the DC-bias mode that can detect single photons arrived at any time. In some cases such as satellite laser ranging and single-photon laser radar where the light pulses arrive regularly, the AC-bias mode enables the SNSPD to work with higher counting rates and lower background dark counts, which however requires complicated readout due to the low signal-to-noise ratio of the photon response. In this work, we report on an AC-biased SNSPD system with a self-differential readout circuit. The system includes a 2-pixel SNSPD consisting of two parallel nanowires, which are biased with 100 MHz sinusoidal current. The output signals of these two nanowires are amplified and combined for the differential readout of the photon response. The resulting response pulse possesses a signal-to-noise ratio ten times higher than that extracted before self-differential readout. In addition, the dark counts are reduced by a factor of 4, and the count rates are increased by a factor of 1.5, in comparison with those under the DC-bias mode. This work provides a specific method to read out the AC-biased SNSPD.

Acta Physica Sinica•Jan 1, 2022•4 citations

Synchronous single-photon detection with GHz-gated superconducting nanowire detectors

Emanuel Knehr, Artem A. Kuzmin, Steffen Doerner +4 more

We demonstrate a GHz-gated operation of superconducting nanowire single-photon detectors suitable for synchronous applications. In comparison with conventional dc-biased nanowire detectors, this method prevents the detector from latching and can suppress dark counts and background noise. Using a gating frequency of 3.8 GHz and a fast, synchronized laser diode, we show that the detector's operation point follows the oscillating current and its detection efficiency depends on the relative frequency and phase of the bias and modulated optical signal. The obtained experimental results are in good agreement with simulations, showing that the duty cycle of a gated detector can be adjusted in a wide range in case of a pronounced saturation of the current-dependent detection efficiency. This operation mode could be suitable for applications such as quantum key distribution and time-of-flight laser ranging.

•Mar 30, 2020•0 citations

Superconducting NbN microstrip single-photon detectors

Alexander A. Korneev

Superconducting Single-Photon Detectors (SSPD) invented two decades ago have evolved to a mature technology and have become devices of choice in the advanced applications of quantum optics, such as quantum cryptography and optical quantum computing. In these applications SSPDs are coupled to single-mode fibers and feature almost unity detection efficiency, negligible dark counts, picosecond timing jitter and MHz photon count rate. Meanwhile, there are great many applications requiring coupling to multi-mode fibers or free space. `Classical’ SSPDs with 100-nm-wide superconducting strip and covering area of about 100 µm2 are not suitable for further scaling due to degradation of performance and low fabrication yield. Recently we have demonstrated single-photon counting in micron-wide superconducting bridges and strips. Here we present our approach to the realization of practical photon-counting detectors of large enough area to be efficiently coupled to multi-mode fibers or free space. The detector is either a meander or a spiral of 1-µm-wide strip covering an area of 50x50 µm2. Being operated at 1.7K temperature it demonstrates the saturated detection efficiency (i.e. limited by the absorption in the detector) up to 1550 nm wavelength, about 10 ns dead time and timing jitter in range 50-100 ps.

Quantum Optics and Photon Counting•Apr 19, 2021•0 citations

Superconducting wide strip photon detector with high critical current bank structure

Masahiro Yabuno, Fumihiro China, Hirotaka Terai +1 more

The single-photon detector is an essential technology in photonic quantum information science and technology. Large-scale photonic quantum computers and quantum networks inevitably require numerous high-performance single-photon detectors. Superconducting nanostrip single-photon detectors (SNSPDs) using around 100-nm-wide nanostrips are promising technologies with high detection efficiency, low dark count, and low jitter, but there has been room for evolution in terms of polarization dependence and productivity. Using wide strips with widths of tens of micrometers provides polarization-independent high detection efficiency and high-yield fabrication using high-throughput photolithography with submicron resolution. However, detecting photons with such wide strips has been challenging due to rapidly increasing intrinsic dark counts caused by the uneven distribution of the superconducting current in the strip. Here, we present a novel superconducting wide strip photon detector (SWSPD) with a high critical current bank (HCCB) structure. This new strip structure suppresses the intrinsic dark counts and provides highly efficient photon detection in the wide strips. We have simultaneously achieved a polarization-independent detection efficiency of over 78% for 1550-nm wavelength photons, a low dark count rate (DCR) of ∼80 cps, and a low jitter of 29.8 ps using a 20-µm-wide SWSPD with the HCCB structure. This result paves the way for a new class of photon detectors using ultra-wide superconducting strips. These photon detectors with excellent productivity and polarization-independent high detection performances would boost the advance of large-scale photonic quantum technologies.

arXiv:2305.06583•Optica Quantum•Sep 29, 2023•20 citations
Superconducting strip single-photon detectors (SSPDs) have demonstrated superior performance in quantum key distribution, high-speed optical communication and et al. However, these applications are constrained by latching effects, dark count rates, and speed of detection, and the rapid detection of single photon events in the target time range requires proper readout means to control. This study presents a nanosecond-level gating filtering circuit with high reliability based on direct current biasing, enabling window-selective photon detection through time-controlled bias current modulation while maintaining superconductivity with reduced current during non-gate intervals. Experimental results show that the proposed scheme achieves a 3 ns–500 ns adjustable gating window and preserving high system detection efficiency and low timing jitter under specific windows. Compared to conventional approaches, the dark count rate is reduced by nearly one orders of magnitude, and the photon dynamic range is significantly expanded.
Superconducting nanowire single-photon detectors (SNSPDs) show near unity efficiency, low dark count rate, and short recovery time. Combining these characteristics with temporal control of SNSPDs broadens their applications as in active de-latching for higher dynamic range counting or temporal filtering for pump-probe spectroscopy or LiDAR. To that end, we demonstrate active gating of an SNSPD with a minimum off-to-on rise time of 2.4 ns and a total gate length of 5.0 ns. We show how the rise time depends on the inductance of the detector in combination with the control electronics. The gate window is demonstrated to be fully and freely, electrically tunable up to 500 ns at a repetition rate of 1.0 MHz, as well as ungated, free-running operation. Control electronics to generate the gating are mounted on the 2.3 K stage of a closed-cycle sorption cryostat, while the detector is operated on the cold stage at 0.8 K. We show that the efficiency and timing jitter of the detector is not altered during the on-time of the gating window. We exploit gated operation to demonstrate a method to increase in the photon counting dynamic range by a factor 11.2, as well as temporal filtering of a strong pump in an emulated pump-probe experiment.
Superconducting nanowire single-photon detectors (SNSPDs) are integral to the fields of quantum information and quantum communication, offering high efficiency, low dark count rate, high count rate, and minimal timing jitter. However, a common challenge with SNSPDs is their propensity for latching and nonlinear count rate increase under high incident photon fluxes due to the traditional external readout circuitry. This issue is primarily caused by large dynamic inductance and the ac-coupled effects of the bias and amplifier capacitors. In this study, we carefully selected a commercial SNSPD with an efficiency of over 95%. To address the aforementioned challenges, we implemented a resistor–inductor-type filter structure, which is directly coupled to a low-temperature amplifier, and their operating temperature is 40 K. Experimental results revealed that the enhanced SNSPD readout circuit achieves a count rate that is approximately 3.5 times greater than that of the traditional circuit. Moreover, the timing jitter of the SNSPD was optimized, decreasing by approximately 3.6 times under high incident photon fluxes. These performance enhancements could significantly improve high-speed optical communication and quantum precision measurement.
Superconducting nanowire single photon detector (SNSPD) has been widely used in many fields such as quantum computing, quantum key distribution and laser radar, due to its high detection efficiency, low dark count rate, high counting rate, and low timing jitter. In most cases, the SNSPD works under the DC-bias mode that can detect single photons arrived at any time. In some cases such as satellite laser ranging and single-photon laser radar where the light pulses arrive regularly, the AC-bias mode enables the SNSPD to work with higher counting rates and lower background dark counts, which however requires complicated readout due to the low signal-to-noise ratio of the photon response. In this work, we report on an AC-biased SNSPD system with a self-differential readout circuit. The system includes a 2-pixel SNSPD consisting of two parallel nanowires, which are biased with 100 MHz sinusoidal current. The output signals of these two nanowires are amplified and combined for the differential readout of the photon response. The resulting response pulse possesses a signal-to-noise ratio ten times higher than that extracted before self-differential readout. In addition, the dark counts are reduced by a factor of 4, and the count rates are increased by a factor of 1.5, in comparison with those under the DC-bias mode. This work provides a specific method to read out the AC-biased SNSPD.
We demonstrate a GHz-gated operation of superconducting nanowire single-photon detectors suitable for synchronous applications. In comparison with conventional dc-biased nanowire detectors, this method prevents the detector from latching and can suppress dark counts and background noise. Using a gating frequency of 3.8 GHz and a fast, synchronized laser diode, we show that the detector's operation point follows the oscillating current and its detection efficiency depends on the relative frequency and phase of the bias and modulated optical signal. The obtained experimental results are in good agreement with simulations, showing that the duty cycle of a gated detector can be adjusted in a wide range in case of a pronounced saturation of the current-dependent detection efficiency. This operation mode could be suitable for applications such as quantum key distribution and time-of-flight laser ranging.
Superconducting Single-Photon Detectors (SSPD) invented two decades ago have evolved to a mature technology and have become devices of choice in the advanced applications of quantum optics, such as quantum cryptography and optical quantum computing. In these applications SSPDs are coupled to single-mode fibers and feature almost unity detection efficiency, negligible dark counts, picosecond timing jitter and MHz photon count rate. Meanwhile, there are great many applications requiring coupling to multi-mode fibers or free space. `Classical’ SSPDs with 100-nm-wide superconducting strip and covering area of about 100 µm2 are not suitable for further scaling due to degradation of performance and low fabrication yield. Recently we have demonstrated single-photon counting in micron-wide superconducting bridges and strips. Here we present our approach to the realization of practical photon-counting detectors of large enough area to be efficiently coupled to multi-mode fibers or free space. The detector is either a meander or a spiral of 1-µm-wide strip covering an area of 50x50 µm2. Being operated at 1.7K temperature it demonstrates the saturated detection efficiency (i.e. limited by the absorption in the detector) up to 1550 nm wavelength, about 10 ns dead time and timing jitter in range 50-100 ps.
The single-photon detector is an essential technology in photonic quantum information science and technology. Large-scale photonic quantum computers and quantum networks inevitably require numerous high-performance single-photon detectors. Superconducting nanostrip single-photon detectors (SNSPDs) using around 100-nm-wide nanostrips are promising technologies with high detection efficiency, low dark count, and low jitter, but there has been room for evolution in terms of polarization dependence and productivity. Using wide strips with widths of tens of micrometers provides polarization-independent high detection efficiency and high-yield fabrication using high-throughput photolithography with submicron resolution. However, detecting photons with such wide strips has been challenging due to rapidly increasing intrinsic dark counts caused by the uneven distribution of the superconducting current in the strip. Here, we present a novel superconducting wide strip photon detector (SWSPD) with a high critical current bank (HCCB) structure. This new strip structure suppresses the intrinsic dark counts and provides highly efficient photon detection in the wide strips. We have simultaneously achieved a polarization-independent detection efficiency of over 78% for 1550-nm wavelength photons, a low dark count rate (DCR) of ∼80 cps, and a low jitter of 29.8 ps using a 20-µm-wide SWSPD with the HCCB structure. This result paves the way for a new class of photon detectors using ultra-wide superconducting strips. These photon detectors with excellent productivity and polarization-independent high detection performances would boost the advance of large-scale photonic quantum technologies.