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Quantum Technologies and Edge Devices in Electrical Grids: Opportunities, Challenges, and Future Directions
Authors:
Marjorie Hoegen,
René Glebke,
M. Sahnawaz Alam,
Alessandro David,
Juan Navarro Arenas,
Nikolaus Wirtz,
Mario Albanese,
Daniele Carta,
Felix Motzoi,
Antonello Monti,
Carsten Schuck,
Andrea Benigni,
Klaus Wehrle,
Ferdinanda Ponci
Abstract:
In modern power systems, edge devices serve as local hubs that collect data, perform on-site computing, sense electrical parameters, execute control actions, and communicate with neighboring edge devices as part of the larger grid. However, as the number of monitored nodes and control loops grows, traditional edge devices face serious limits. They can become overloaded by complex signal processing…
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In modern power systems, edge devices serve as local hubs that collect data, perform on-site computing, sense electrical parameters, execute control actions, and communicate with neighboring edge devices as part of the larger grid. However, as the number of monitored nodes and control loops grows, traditional edge devices face serious limits. They can become overloaded by complex signal processing and decision tasks, causing delays and higher energy use. Standard sensors hit a noise floor that prevents them from detecting miniature changes, making it harder to spot early signs of faults or instability. Meanwhile, conventional communication links struggle with bandwidth limits, security risks, and rising encryption demands, which together slow down and weaken the transfer of critical grid information. Quantum technologies have the potential to overcome these challenges. Quantum computers can deliver exponential speed-ups for optimization and machine-learning tasks that ordinary processors cannot handle. Quantum sensors can sense signals with atomic precision, giving edge devices a more precise view of grid dynamics. Quantum communication techniques, including quantum key distribution, offer methods to achieve information-theoretic security and ensure that information arrives quickly and without tampering. We explore how quantum technologies can be integrated into edge devices, highlighting both opportunities and challenges.
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Submitted 6 March, 2026;
originally announced March 2026.
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The QTF-Backbone: Proposal for a Nationwide Optical Fibre Backbone in Germany for Quantum Technology and Time and Frequency Metrology
Authors:
Tara Cubel Liebisch,
Peter Kaufmann,
Harald Schnatz,
Susanne Naegele-Jackson,
Jochen Kronjäger,
Klaus Blaum,
Stefan Kück,
Dieter Meschede,
Stephan Schiller,
Laura Agazzi,
Soroosh Alighanbari,
Joachim Ankerhold,
Georgy V. Astakhov,
Stefanie Barz,
Ingo Baumann,
Rainer Baumgart,
Christoph Becher,
Hendrik Bekker,
Oliver Benson,
Paolo Bianco,
Ronald Bieber,
Immanuel Bloch,
Ulrike Blumröder,
Rainer Bockholt,
Johannes Bouman
, et al. (144 additional authors not shown)
Abstract:
The recent breakthroughs in the distribution of quantum information and high-precision time and frequency (T&F) signals over long-haul optical fibre networks have transformative potential for physically secure communications, resilience of timing infrastructure (such as that supporting Global Navigation Satellite Systems (GNSS)) and fundamental physics. To date, these capabilities remain confined…
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The recent breakthroughs in the distribution of quantum information and high-precision time and frequency (T&F) signals over long-haul optical fibre networks have transformative potential for physically secure communications, resilience of timing infrastructure (such as that supporting Global Navigation Satellite Systems (GNSS)) and fundamental physics. To date, these capabilities remain confined to isolated testbeds, with quantum and T&F signals accessible, for example in Germany, to only a few institutions. In this white paper we propose the QTF Backbone: a dedicated national fibre-optic infrastructure in Germany for the networked distribution of Quantum and T&F signals using dark fibres and specialised hardware. The QTF Backbone is planned as a four-phase deployment over ten years to ensure scalable, sustainable access for research institutions and industry. The concept builds on successful demonstrations of time and frequency distribution at high Technology Readiness Levels (TRLs) across Europe, including PTB-MPQ links in Germany, REFIMEVE in France, and the Italian LIFT network. The QTF Backbone will enable transformative Research and Development (R&D), support a nationwide QTF ecosystem, and ensure the transition from innovation to deployment. As a national and European hub, it will position Germany and Europe at the forefront of quantum networking, as well as T&F transfer.
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Submitted 16 August, 2026; v1 submitted 4 June, 2025;
originally announced June 2025.
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Multi-photon enhanced resolution for Superconducting Nanowire Single-Photon Detector-based Time-of-Flight lidar systems
Authors:
Adrian S. Abazi,
Roland Jaha,
Connor A. Graham-Scott,
Wolfram H. P. Pernice,
Carsten Schuck
Abstract:
Superconducting nanowire single photon detectors (SNSPDs) emerged in the last decade as a disruptive technology that features performance characteristics, such as high sensitivity, dynamic range and temporal accuracy, which are ideally suited for light detection and ranging (lidar) applications. Here, we report a time-of-flight (TOF) lidar system based on waveguide-integrated SNSPDs that excels in…
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Superconducting nanowire single photon detectors (SNSPDs) emerged in the last decade as a disruptive technology that features performance characteristics, such as high sensitivity, dynamic range and temporal accuracy, which are ideally suited for light detection and ranging (lidar) applications. Here, we report a time-of-flight (TOF) lidar system based on waveguide-integrated SNSPDs that excels in temporal accuracy, which translates into high range resolution. For single-shot measurements, we find resolution in the millimeter regime, resulting from the jitter of the time-of-flight signal of 21$\,$ps for low photon numbers. We further decrease this signal jitter to 11$\,$ps by driving the SNSPD into a multiphoton detection regime, utilizing laser pulses of higher intensity, thus improving range resolution. For multi-shot measurements we find sub-millimeter range-accuracy of 0.75$\,$mm and reveal additional surface information of scanned objects by visualizing the number of reflected photons and their temporal spread with the acquired range data in a combined representation. Our realization of a lidar receiver exploits favorable timing accuracy of waveguide-integrated SNSPDs and extends their operation to the multiphoton regime, which benefits a wide range of remote sensing applications.
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Submitted 19 March, 2025;
originally announced March 2025.
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Kinetic Inductance and Jitter Dependence of the Intrinsic Photon Number Resolution in Superconducting Nanowire Single-Photon Detectors
Authors:
Roland Jaha,
Connor A. Graham-Scott,
Adrian S. Abazi,
Wolfram Pernice,
Carsten Schuck,
Simone Ferrari
Abstract:
The ability to resolve photon numbers is crucial in quantum information science and technology, driving the development of detectors with intrinsic photon-number resolving (PNR) capabilities. Although transition edge sensors represent the state-of-the-art in PNR performance, superconducting nanowire single-photon detectors (SNSPDs) offer superior efficiency, speed, noise reduction, and timing prec…
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The ability to resolve photon numbers is crucial in quantum information science and technology, driving the development of detectors with intrinsic photon-number resolving (PNR) capabilities. Although transition edge sensors represent the state-of-the-art in PNR performance, superconducting nanowire single-photon detectors (SNSPDs) offer superior efficiency, speed, noise reduction, and timing precision. Directly inferring photon numbers, however, has only recently become feasible due to advances in readout technology. Despite this, photon-number discrimination remains constrained by the nanowire's electrical properties and readout jitter. In this work, we employ waveguide-integrated SNSPDs and time-resolved measurements to explore how the nanowire kinetic inductance and system jitter affect PNR capabilities. By analyzing the latency time of the photon detection, we can resolve changes in the rising edge of the detection pulse. We find that lower jitter as well as increased kinetic inductance enhances the pulse separation for different photon numbers and improves the PNR capability. Enhancing the kinetic inductance from 165 nH to 872 nH improves PNR quality by 12%, 31% and 23% over the first three photon numbers, though at the cost of reducing the detector's count rate from 165 Mcps to 19 Mcps. Our findings highlight the trade-off between PNR resolution and detector speed.
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Submitted 30 October, 2024;
originally announced October 2024.
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Toward integrated tantalum pentoxide optical parametric oscillators
Authors:
Maximilian Timmerkamp,
Niklas M. Lüpken,
Shqiprim Adrian Abazi,
Julian Rasmus Bankwitz,
Carsten Schuck,
Carsten Fallnich
Abstract:
We present a hybrid waveguide-fiber optical parametric oscillator (OPO) exploiting degenerate four-wave mixing in tantalum pentoxide. The OPO, pumped with ultrashort pulses at 1.55 $μ$m wavelength, generated tunable idler pulses with up to 4.1 pJ energy tunable between 1.63 $μ$m and 1.68 $μ$m center wavelength. An upper bound for the total tolerable cavity loss of 32 dB was found, rendering a chip…
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We present a hybrid waveguide-fiber optical parametric oscillator (OPO) exploiting degenerate four-wave mixing in tantalum pentoxide. The OPO, pumped with ultrashort pulses at 1.55 $μ$m wavelength, generated tunable idler pulses with up to 4.1 pJ energy tunable between 1.63 $μ$m and 1.68 $μ$m center wavelength. An upper bound for the total tolerable cavity loss of 32 dB was found, rendering a chip-integrated OPO feasible as a compact and robust light source.
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Submitted 8 June, 2023;
originally announced June 2023.
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Inverse Design of Nanophotonic Devices using Dynamic Binarization
Authors:
Marco Butz,
Adrian S. Abazi,
Rene Ross,
Benjamin Risse,
Carsten Schuck
Abstract:
The complexity of applications addressed with photonic integrated circuits is steadily rising and poses increasingly challenging demands on individual component functionality, performance and footprint. Inverse design methods have recently shown great promise to address these demands using fully automated design procedures that enable access to non-intuitive device layouts beyond conventional nano…
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The complexity of applications addressed with photonic integrated circuits is steadily rising and poses increasingly challenging demands on individual component functionality, performance and footprint. Inverse design methods have recently shown great promise to address these demands using fully automated design procedures that enable access to non-intuitive device layouts beyond conventional nanophotonic design concepts. Here we present a dynamic binarization method for the objective-first algorithm that lies at the core of the currently most successful inverse design algorithms. Our results demonstrate significant performance advantages over previous implementations of objective first algorithms, which we show for a fundamental TE00 to TE20 waveguide mode converter both in simulation and in experiments with fabricated devices.
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Submitted 18 November, 2022;
originally announced November 2022.
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Scaling waveguide-integrated superconducting nanowire single-photon detector solutions to large numbers of independent optical channels
Authors:
Matthias Häußler,
Robin Terhaar,
Martin A. Wolff,
Helge Gehring,
Fabian Beutel,
Wladick Hartmann,
Nicolai Walter,
Max Tillmann,
Mahdi Ahangarianabhari,
Michael Wahl,
Tino Röhlicke,
Hans-Jürgen Rahn,
Wolfram H. P. Pernice,
Carsten Schuck
Abstract:
Superconducting nanowire single-photon detectors are an enabling technology for modern quantum information science and are gaining attractiveness for the most demanding photon counting tasks in other fields. Embedding such detectors in photonic integrated circuits enables additional counting capabilities through nanophotonic functionalization. Here we show how a scalable number of waveguide-integr…
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Superconducting nanowire single-photon detectors are an enabling technology for modern quantum information science and are gaining attractiveness for the most demanding photon counting tasks in other fields. Embedding such detectors in photonic integrated circuits enables additional counting capabilities through nanophotonic functionalization. Here we show how a scalable number of waveguide-integrated superconducting nanowire single-photon detectors can be interfaced with independent fiber optic channels on the same chip. Our plug-and-play detector package is hosted inside a compact and portable closed-cycle cryostat providing cryogenic signal amplification for up to 64 channels. We demonstrate state-of-the-art photon counting performance with up to 60 % system detection efficiency and down to 26.0 ps timing accuracy for individually addressable detectors. Our multi-channel single photon receiver offers exciting measurement capabilities for future quantum communication, remote sensing and imaging applications.
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Submitted 25 July, 2022;
originally announced July 2022.
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Ultrafast quantum key distribution using fully parallelized quantum channels
Authors:
Robin Terhaar,
Jasper Rödiger,
Matthias Häußler,
Michael Wahl,
Helge Gehring,
Martin A. Wolff,
Fabian Beutel,
Wladick Hartmann,
Nicolai Walter,
Jonas Hanke,
Peter Hanne,
Nino Walenta,
Maximilian Diedrich,
Nicolas Perlot,
Max Tillmann,
Tino Röhlicke,
Mahdi Ahangarianabhari,
Carsten Schuck,
Wolfram H. P. Pernice
Abstract:
The field of quantum information processing offers secure communication protected by the laws of quantum mechanics and is on the verge of finding wider application for information transfer of sensitive data. To overcome the obstacle of inadequate cost-efficiency, extensive research is being done on the many components required for high data throughput using quantum key distribution (QKD). Aiming f…
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The field of quantum information processing offers secure communication protected by the laws of quantum mechanics and is on the verge of finding wider application for information transfer of sensitive data. To overcome the obstacle of inadequate cost-efficiency, extensive research is being done on the many components required for high data throughput using quantum key distribution (QKD). Aiming for an application-oriented solution, we report on the realization of a multichannel QKD system for plug-and-play high-bandwidth secure communication at telecom wavelength. For this purpose, a rack-sized multichannel superconducting nanowire single photon detector (SNSPD) system, as well as a highly parallelized time-correlated single photon counting (TCSPC) unit have been developed and linked to an FPGA-controlled QKD evaluation setup allowing for continuous operation and achieving high secret key rates using a coherent-one-way protocol.
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Submitted 19 July, 2022; v1 submitted 15 July, 2022;
originally announced July 2022.
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Single photon emission from individual nanophotonic-integrated colloidal quantum dots
Authors:
Alexander Eich,
Tobias C. Spiekermann,
Helge Gehring,
Lisa Sommer,
Julian R. Bankwitz,
Philip P. J. Schrinner,
Johann A. Preuß,
Steffen Michaelis de Vasconcellos,
Rudolf Bratschitsch,
Wolfram H. P. Pernice,
Carsten Schuck
Abstract:
Solution processible colloidal quantum dots hold great promise for realizing single-photon sources embedded into scalable quantum technology platforms. However, the high-yield integration of large numbers of individually addressable colloidal quantum dots in a photonic circuit has remained an outstanding challenge. Here, we report on integrating individual colloidal core-shell quantum dots (CQDs)…
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Solution processible colloidal quantum dots hold great promise for realizing single-photon sources embedded into scalable quantum technology platforms. However, the high-yield integration of large numbers of individually addressable colloidal quantum dots in a photonic circuit has remained an outstanding challenge. Here, we report on integrating individual colloidal core-shell quantum dots (CQDs) into a nanophotonic network that allows for excitation and efficient collection of single-photons via separate waveguide channels. An iterative electron beam lithography process provides a viable method to position single emitters at predefined positions in a photonic integrated circuit with yield that approaches unity. Our work moves beyond the bulk optic paradigm of confocal microscopy and paves the way for supplying chip-scale quantum networks with single photons from large numbers of simultaneously controllable quantum emitters.
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Submitted 13 January, 2022; v1 submitted 23 April, 2021;
originally announced April 2021.
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Single-photon detection and cryogenic reconfigurability in Lithium Niobate nanophotonic circuits
Authors:
Emma Lomonte,
Martin A. Wolff,
Fabian Beutel,
Simone Ferrari,
Carsten Schuck,
Wolfram H. P. Pernice,
Francesco Lenzini
Abstract:
Lithium-Niobate-On-Insulator (LNOI) is emerging as a promising platform for integrated quantum photonic technologies because of its high second-order nonlinearity and compact waveguide footprint. Importantly, LNOI allows for creating electro-optically reconfigurable circuits, which can be efficiently operated at cryogenic temperature. Their integration with superconducting nanowire single-photon d…
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Lithium-Niobate-On-Insulator (LNOI) is emerging as a promising platform for integrated quantum photonic technologies because of its high second-order nonlinearity and compact waveguide footprint. Importantly, LNOI allows for creating electro-optically reconfigurable circuits, which can be efficiently operated at cryogenic temperature. Their integration with superconducting nanowire single-photon detectors (SNSPDs) paves the way for realizing scalable photonic devices for active manipulation and detection of quantum states of light. Here we report the first demonstration of these two key components integrated in a low loss (0.2 dB/cm) LNOI waveguide network. As an experimental showcase of our technology, we demonstrate the combined operation of an electrically tunable Mach-Zehnder interferometer and two waveguide-integrated SNSPDs at its outputs. We show static reconfigurability of our system with a bias-drift-free operation over a time of 12 hours, as well as high-speed modulation at a frequency up to 1 GHz. Our results provide blueprints for implementing complex quantum photonic devices on the LNOI platform.
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Submitted 25 November, 2021; v1 submitted 19 March, 2021;
originally announced March 2021.
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Optimal photonic crystal cavities for coupling nanoemitters to photonic integrated circuits
Authors:
Jan Olthaus,
Philip P. J. Schrinner,
Doris E. Reiter,
Carsten Schuck
Abstract:
Photonic integrated circuits that are manufactured with mature semiconductor technology hold great promise for realizing scalable quantum technology. Efficient interfaces between quantum emitters and nanophotonic devices are crucial building blocks for such implementations on silicon chips. These interfaces can be realized as nanobeam optical cavities with high quality factors and wavelength-scale…
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Photonic integrated circuits that are manufactured with mature semiconductor technology hold great promise for realizing scalable quantum technology. Efficient interfaces between quantum emitters and nanophotonic devices are crucial building blocks for such implementations on silicon chips. These interfaces can be realized as nanobeam optical cavities with high quality factors and wavelength-scale mode volumes, thus providing enhanced coupling between nanoscale quantum emitters and nanophotonic circuits. Realizing such resonant structures is particularly challenging for the visible wavelength range, where many of the currently considered quantum emitters operate, and if compatibility with modern semiconductor nanofabrication processes is desired. Here we show that photonic crystal nanobeam cavities for the visible spectrum can be designed and fabricated directly on-substrate with high quality factors and small mode volumes. We compare designs based on deterministic and mode-matching methods and find the latter advantageous for on-substrate realizations. Our results pave the way for integrating quantum emitters with nanophotonic circuits for applications in quantum technology.
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Submitted 5 September, 2019;
originally announced September 2019.
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Parametric down-conversion photon pair source on a nanophotonic chip
Authors:
Xiang Guo,
Chang-ling Zou,
Carsten Schuck,
Hojoong Jung,
Risheng Cheng,
Hong X. Tang
Abstract:
Quantum photonic chips, which integrate quantum light sources alongside active and passive optical elements, as well as single photon detectors, show great potential for photonic quantum information processing and quantum technology. Mature semiconductor nanofabrication processes allow for scaling such photonic integrated circuits to on-chip networks of increasing complexity. Second order nonlinea…
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Quantum photonic chips, which integrate quantum light sources alongside active and passive optical elements, as well as single photon detectors, show great potential for photonic quantum information processing and quantum technology. Mature semiconductor nanofabrication processes allow for scaling such photonic integrated circuits to on-chip networks of increasing complexity. Second order nonlinear materials are the method of choice for generating photonic quantum states in the overwhelming part of linear optic experiments using bulk components but integration with waveguide circuitry on a nanophotonic chip proved to be challenging. Here we demonstrate such an on-chip parametric down-conversion source of photon pairs based on second order nonlinearity in an Aluminum nitride microring resonator. We show the potential of our source for quantum information processing by measuring high-visibility antibunching of heralded single photons with nearly ideal state purity. Our down conversion source operates with high brightness and low noise, yielding pairs of correlated photons at MHz-rates with high coincidence-to-accidental ratio. The generated photon pairs are spectrally far separated from the pump field, providing good potential for realizing sufficient on-chip filtering and monolithic integration of quantum light sources, waveguide circuits and single photon detectors.
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Submitted 11 March, 2016;
originally announced March 2016.
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Quantum interference in heterogeneous superconducting-photonic circuits on a silicon chip
Authors:
Carsten Schuck,
Xiang Guo,
Linran Fan,
Xiao-Song Ma,
Menno Poot,
Hong X. Tang
Abstract:
Quantum information processing holds great promise for communicating and computing data efficiently. However, scaling current photonic implementation approaches to larger system size remains an outstanding challenge for realizing disruptive quantum technology. Two main ingredients of quantum information processors are quantum interference and single-photon detectors. Here we develop a hybrid super…
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Quantum information processing holds great promise for communicating and computing data efficiently. However, scaling current photonic implementation approaches to larger system size remains an outstanding challenge for realizing disruptive quantum technology. Two main ingredients of quantum information processors are quantum interference and single-photon detectors. Here we develop a hybrid superconducting-photonic circuit system to show how these elements can be combined in a scalable fashion on a silicon chip. We demonstrate the suitability of this approach for integrated quantum optics by interfering and detecting photon pairs directly on the chip with waveguide-coupled single-photon detectors. Using a directional coupler implemented with silicon nitride nanophotonic waveguides, we observe 97% interference visibility when measuring photon statistics with two monolithically integrated superconducting single photon detectors. The photonic circuit and detector fabrication processes are compatible with standard semiconductor thin-film technology, making it possible to implement more complex and larger scale quantum photonic circuits on silicon chips.
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Submitted 22 November, 2015;
originally announced November 2015.
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On-chip interaction-free measurements via the quantum Zeno effect
Authors:
Xiao-song Ma,
Xiang Guo,
Carsten Schuck,
King Y. Fong,
Liang Jiang,
Hong X. Tang
Abstract:
Although interference is a classical-wave phenomenon, the superposition principle, which underlies interference of individual particles, is at the heart of quantum physics. An interaction-free measurements (IFM) harnesses the wave-particle duality of single photons to sense the presence of an object via the modification of the interference pattern, which can be accomplished even if the photon and…
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Although interference is a classical-wave phenomenon, the superposition principle, which underlies interference of individual particles, is at the heart of quantum physics. An interaction-free measurements (IFM) harnesses the wave-particle duality of single photons to sense the presence of an object via the modification of the interference pattern, which can be accomplished even if the photon and the object haven't interacted with each other. By using the quantum Zeno effect, the efficiency of an IFM can be made arbitrarily close to unity. Here we report an on-chip realization of the IFM based on silicon photonics. We exploit the inherent advantages of the lithographically written waveguides: excellent interferometric phase stability and mode matching, and obtain multipath interference with visibility above 98%. We achieved a normalized IFM efficiency up to 68.2%, which exceeds the 50% limit of the original IFM proposal.
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Submitted 8 May, 2014;
originally announced May 2014.
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Integrated GaN photonic circuits on silicon (100) for second harmonic generation
Authors:
Chi Xiong,
Wolfram Pernice,
Kevin K. Ryu,
Carsten Schuck,
King Y. Fong,
Tomas Palacios,
Hong X. Tang
Abstract:
We demonstrate second order optical nonlinearity in a silicon architecture through heterogeneous integration of single-crystalline gallium nitride (GaN) on silicon (100) substrates. By engineering GaN microrings for dual resonance around 1560 nm and 780 nm, we achieve efficient, tunable second harmonic generation at 780 nm. The \{chi}(2) nonlinear susceptibility is measured to be as high as 16 plu…
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We demonstrate second order optical nonlinearity in a silicon architecture through heterogeneous integration of single-crystalline gallium nitride (GaN) on silicon (100) substrates. By engineering GaN microrings for dual resonance around 1560 nm and 780 nm, we achieve efficient, tunable second harmonic generation at 780 nm. The \{chi}(2) nonlinear susceptibility is measured to be as high as 16 plus minus 7 pm/V. Because GaN has a wideband transparency window covering ultraviolet, visible and infrared wavelengths, our platform provides a viable route for the on-chip generation of optical wavelengths in both the far infrared and near-UV through a combination of \{chi}(2) enabled sum-/difference-frequency processes.
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Submitted 20 January, 2014;
originally announced January 2014.
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Waveguide integrated low noise NbTiN nanowire single-photon detectors with milli-Hz dark count rate
Authors:
Carsten Schuck,
Wolfram H. P. Pernice,
Hong X. Tang
Abstract:
Superconducting nanowire single-photon detectors are an ideal match for integrated quantum photonic circuits due to their high detection efficiency for telecom wavelength photons. Quantum optical technology also requires single-photon detection with low dark count rate and high timing accuracy. Here we present very low noise superconducting nanowire single-photon detectors based on NbTiN thin film…
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Superconducting nanowire single-photon detectors are an ideal match for integrated quantum photonic circuits due to their high detection efficiency for telecom wavelength photons. Quantum optical technology also requires single-photon detection with low dark count rate and high timing accuracy. Here we present very low noise superconducting nanowire single-photon detectors based on NbTiN thin films patterned directly on top of Si3N4 waveguides. We systematically investigate a large variety of detector designs and characterize their detection noise performance. Milli-Hz dark count rates are demonstrated over the entire operating range of the nanowire detectors which also feature low timing jitter. The ultra-low dark count rate, in combination with the high detection efficiency inherent to our traveling wave detector geometry, gives rise to a measured noise equivalent power at the 10^(-20) W/Hz^(1/2) level.
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Submitted 1 June, 2013;
originally announced June 2013.
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Optical time domain reflectometry with low noise waveguide-coupled superconducting nanowire single-photon detectors
Authors:
Carsten Schuck,
Wolfram H. P. Pernice,
Xiaosong Ma,
Hong X. Tang
Abstract:
We demonstrate optical time domain reflectometry over 200 km of optical fiber using low-noise NbTiN superconducting single-photon detectors integrated with Si3N4 waveguides. Our small detector footprint enables high timing resolution of 50ps and a dark count rate of 3 Hz with unshielded fibers, allowing for identification of defects along the fiber over a dynamic range of 37.4 dB. Photons scattere…
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We demonstrate optical time domain reflectometry over 200 km of optical fiber using low-noise NbTiN superconducting single-photon detectors integrated with Si3N4 waveguides. Our small detector footprint enables high timing resolution of 50ps and a dark count rate of 3 Hz with unshielded fibers, allowing for identification of defects along the fiber over a dynamic range of 37.4 dB. Photons scattered and reflected back from the fiber under test can be detected in free-running mode without showing dead zones or other impairments often encountered in semiconductor photon-counting optical time domain reflectometers.
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Submitted 30 May, 2013;
originally announced May 2013.
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Nonlinear optical effects of ultrahigh-Q silicon photonic nanocavities immersed in superfluid helium
Authors:
Xiankai Sun,
Xufeng Zhang,
Carsten Schuck,
Hong X. Tang
Abstract:
Photonic nanocavities are a key component in many applications because of their capability of trapping and storing photons and enhancing interactions of light with various functional materials and structures. The maximal number of photons that can be stored in silicon photonic cavities is limited by the free-carrier and thermo-optic effects at room temperature. To reduce such effects, we performed…
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Photonic nanocavities are a key component in many applications because of their capability of trapping and storing photons and enhancing interactions of light with various functional materials and structures. The maximal number of photons that can be stored in silicon photonic cavities is limited by the free-carrier and thermo-optic effects at room temperature. To reduce such effects, we performed the first experimental study of optical nonlinearities in ultrahigh-Q silicon disk nanocavities at cryogenic temperatures in a superfluid helium environment. At elevated input power, the cavity transmission spectra exhibit distinct blue-shifted bistability behavior when temperature crosses the liquid helium lambda point. At even lower temperatures, the spectra restore to symmetric Lorentzian shapes. Under this condition, we obtain a large stored intracavity photon number of about 40,000, which is limited ultimately by the local helium phase transition. These new discoveries are explained by theoretical calculations and numerical simulations.
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Submitted 28 February, 2013;
originally announced February 2013.
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Matrix of integrated superconducting single-photon detectors with high timing resolution
Authors:
Carsten Schuck,
Wolfram H. P. Pernice,
Olga Minaeva,
Mo Li,
Gregory Gol'tsman,
Alexander V. Sergienko,
Hong X. Tang
Abstract:
We demonstrate a large grid of individually addressable superconducting single photon detectors on a single chip. Each detector element is fully integrated into an independent waveguide circuit with custom functionality at telecom wavelengths. High device density is achieved by fabricating the nanowire detectors in traveling wave geometry directly on top of silicon-on-insulator waveguides. Our sup…
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We demonstrate a large grid of individually addressable superconducting single photon detectors on a single chip. Each detector element is fully integrated into an independent waveguide circuit with custom functionality at telecom wavelengths. High device density is achieved by fabricating the nanowire detectors in traveling wave geometry directly on top of silicon-on-insulator waveguides. Our superconducting single-photon detector matrix includes detector designs optimized for high detection efficiency, low dark count rate and high timing accuracy. As an example, we exploit the high timing resolution of a particularly short nanowire design to resolve individual photon round-trips in a cavity ring-down measurement of a silicon ring resonator.
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Submitted 5 February, 2013;
originally announced February 2013.
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NbTiN superconducting nanowire detectors for visible and telecom wavelengths single photon counting on Si3N4 photonic circuits
Authors:
C. Schuck,
W. H. P. Pernice,
H. X. Tang
Abstract:
We demonstrate niobium titanium nitride superconducting nanowires patterned on stoichiometric silicon nitride waveguides for detecting visible and infrared photons. The use of silicon nitride on insulator on silicon substrates allows us to simultaneously realize photonic circuits for visible and infrared light and integrate them with nanowire detectors directly on-chip. By implementing a traveling…
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We demonstrate niobium titanium nitride superconducting nanowires patterned on stoichiometric silicon nitride waveguides for detecting visible and infrared photons. The use of silicon nitride on insulator on silicon substrates allows us to simultaneously realize photonic circuits for visible and infrared light and integrate them with nanowire detectors directly on-chip. By implementing a traveling wave detector geometry in this material platform, we achieve efficient single photon detection for both wavelength regimes. Our detectors are an ideal match for integrated quantum optics as they provide crucial functionality on a wideband transparent waveguide material.
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Submitted 4 February, 2013;
originally announced February 2013.
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Aluminum nitride as a new material for chip-scale optomechanics and nonlinear optics
Authors:
Chi Xiong,
Wolfram H. P. Pernice,
Xiankai Sun,
Carsten Schuck,
King Y. Fong,
Hong X. Tang
Abstract:
Silicon photonics has offered a versatile platform for the recent development of integrated optomechanical circuits. However, silicon is limited to wavelengths above 1100 nm and does not allow device operation in the visible spectrum range where low noise lasers are conveniently available. The narrow band gap of silicon also makes silicon optomechanical devices susceptible to strong two-photon abs…
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Silicon photonics has offered a versatile platform for the recent development of integrated optomechanical circuits. However, silicon is limited to wavelengths above 1100 nm and does not allow device operation in the visible spectrum range where low noise lasers are conveniently available. The narrow band gap of silicon also makes silicon optomechanical devices susceptible to strong two-photon absorption and free carrier absorption, which often introduce strong thermal effect that limit the devices' stability and cooling performance. Further, silicon also does not provide the desired lowest order optical nonlinearity for interfacing with other active electrical components on a chip. On the other hand, aluminum nitride (AlN) is a wideband semiconductor widely used in micromechanical resonators due to its low mechanical loss and high electromechanical coupling strength. Here we report the development of AlN-on-silicon platform for low loss, wideband optical guiding, as well as its use for achieving simultaneous high optical quality and mechanical quality optomechanical devices. Exploiting AlN's inherent second order nonlinearity we further demonstrate electro-optic modulation and efficient second-harmonic generation in AlN photonic circuits. Our results suggest that low cost AlN-on-silicon photonic circuits are excellent substitutes for CMOS-compatible photonic circuits for building new functional optomechanical devices that are free from carrier effects.
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Submitted 3 October, 2012;
originally announced October 2012.
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Second harmonic generation in phase matched aluminum nitride waveguides
Authors:
W. H. P. Pernice,
C. Xiong,
C. Schuck,
H. X. Tang
Abstract:
We demonstrate second order optical nonlinearity in aluminum nitride on insulator substrates. Using sputter-deposited aluminum nitride thin films we realize nanophotonic waveguides coupled to micro-ring resonators that simultaneously support cavity resonant modes for both visible and IR light. By using phase matched ring resonators, we achieve efficient second-harmonic generation and are able to g…
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We demonstrate second order optical nonlinearity in aluminum nitride on insulator substrates. Using sputter-deposited aluminum nitride thin films we realize nanophotonic waveguides coupled to micro-ring resonators that simultaneously support cavity resonant modes for both visible and IR light. By using phase matched ring resonators, we achieve efficient second-harmonic generation and are able to generate up to 0.5uW of visible light on the chip with a conversion efficiency of -46dB. From the measured response we obtain a second order non-linear susceptibility (\c{hi}2) of 4.7pm/V. Our platform provides a viable route for realizing wideband linear and nonlinear optical devices on a chip.
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Submitted 15 May, 2012;
originally announced May 2012.
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High-Q aluminum nitride photonic crystal nanobeam cavities
Authors:
W. H. P. Pernice,
C. Xiong,
C. Schuck,
H. X. Tang
Abstract:
We demonstrate high optical quality factors in aluminum nitride (AlN) photonic crystal nanobeam cavities. Suspended AlN photonic crystal nanobeams are fabricated in sputter-deposited AlN-on-insulator substrates using a self-protecting release process. Employing one-dimensional photonic crystal cavities coupled to integrated optical circuits we measure quality factors up to 146,000. By varying the…
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We demonstrate high optical quality factors in aluminum nitride (AlN) photonic crystal nanobeam cavities. Suspended AlN photonic crystal nanobeams are fabricated in sputter-deposited AlN-on-insulator substrates using a self-protecting release process. Employing one-dimensional photonic crystal cavities coupled to integrated optical circuits we measure quality factors up to 146,000. By varying the waveguide-cavity coupling gap, extinction ratios in excess of 15 dB are obtained. Our results open the door for integrated photonic bandgap structures made from a low loss, wide-transparency, nonlinear optical material system.
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Submitted 7 May, 2012;
originally announced May 2012.
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High Speed and High Efficiency Travelling Wave Single-Photon Detectors Embedded in Nanophotonic Circuits
Authors:
W. Pernice,
C. Schuck,
O. Minaeva,
M. Li,
G. N. Goltsman,
A. V. Sergienko,
H. X. Tang
Abstract:
Ultrafast, high quantum efficiency single photon detectors are among the most sought-after elements in modern quantum optics and quantum communication. High photon detection efficiency is essential for scalable measurement-based quantum computation, quantum key distribution, and loophole-free Bell experiments. However, imperfect modal matching and finite photon absorption rates have usually limite…
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Ultrafast, high quantum efficiency single photon detectors are among the most sought-after elements in modern quantum optics and quantum communication. High photon detection efficiency is essential for scalable measurement-based quantum computation, quantum key distribution, and loophole-free Bell experiments. However, imperfect modal matching and finite photon absorption rates have usually limited the maximum attainable detection efficiency of single photon detectors. Here we demonstrate a superconducting nanowire detector atop nanophotonic waveguides which allows us to drastically increase the absorption length for incoming photons. When operating the detectors close to the critical current we achieve high on-chip single photon detection efficiency up to 91% at telecom wavelengths, with uncertainty dictated by the variation of the waveguide photon flux. We also observe remarkably low dark count rates without significant compromise of detection efficiency. Furthermore, our detectors are fully embedded in a scalable silicon photonic circuit and provide ultrashort timing jitter of 18ps. Exploiting this high temporal resolution we demonstrate ballistic photon transport in silicon ring resonators. The direct implementation of such a detector with high quantum efficiency, high detection speed and low jitter time on chip overcomes a major barrier in integrated quantum photonics.
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Submitted 4 April, 2012; v1 submitted 26 August, 2011;
originally announced August 2011.
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Two-color photoionization of calcium using SHG and LED light
Authors:
C. Schuck,
F. Rohde,
M. Almendros,
M. Hennrich,
J. Eschner
Abstract:
We present a photoionization method to load single 40Ca ions in a linear Paul trap from an atomic beam. Neutral Ca I atoms are resonantly excited from the ground state to the intermediate 4s4p 1P_1-level using coherent 423nm radiation produced by single-pass second harmonic generation in a periodically poled KTiOPO_4 crystal pumped with an 120mW extended cavity diode laser. Ionization is then at…
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We present a photoionization method to load single 40Ca ions in a linear Paul trap from an atomic beam. Neutral Ca I atoms are resonantly excited from the ground state to the intermediate 4s4p 1P_1-level using coherent 423nm radiation produced by single-pass second harmonic generation in a periodically poled KTiOPO_4 crystal pumped with an 120mW extended cavity diode laser. Ionization is then attained with a high-power light emitting diode imaged to the trap center, using an appropriately designed optical system composed of standard achromatic doublet lenses. The setup simplifies previous implementations at similar efficiency, and it hardly requires any maintenance at all.
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Submitted 19 November, 2009;
originally announced November 2009.
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A diode laser stabilization scheme for 40Ca+ single ion spectroscopy
Authors:
F. Rohde,
M. Almendros,
C. Schuck,
J. Huwer,
M. Hennrich,
J. Eschner
Abstract:
We present a scheme for stabilizing multiple lasers at wavelengths between 795 and 866 nm to the same atomic reference line. A reference laser at 852 nm is stabilized to the Cs D2 line using a Doppler-free frequency modulation technique. Through transfer cavities, four lasers are stabilized to the relevant atomic transitions in 40Ca+. The rms linewidth of a transfer-locked laser is measured to b…
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We present a scheme for stabilizing multiple lasers at wavelengths between 795 and 866 nm to the same atomic reference line. A reference laser at 852 nm is stabilized to the Cs D2 line using a Doppler-free frequency modulation technique. Through transfer cavities, four lasers are stabilized to the relevant atomic transitions in 40Ca+. The rms linewidth of a transfer-locked laser is measured to be 123 kHz with respect to an independent atomic reference, the Rb D1 line. This stability is confirmed by the comparison of an excitation spectrum of a single 40Ca+ ion to an eight-level Bloch equation model. The measured Allan variance of 10^(-22) at 10 s demonstrates a high degree of stability for time scales up to 100 s.
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Submitted 6 October, 2009;
originally announced October 2009.