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

International Symposium on Ultrafast Phenomena and Terahertz Waves (ISUPTW)

Influence analysis of gap distance between single-mode fiber and transition edge single-photon sensors

Peizhan Li, Jiaqiang Zhong, Yue Geng, Wen Zhang, Zheng Wang, Sheng‐Cai Shi

Published Sep 9, 2021• 3 citations
Publisher

Abstract

Optical transition-edge sensor (TES) with high quantum efficiency, low dark count rate, and high energy resolution has been used in quantum information and communications. The gap distance between the fiber tip and TES has an influence on the TES performance. Here we measured the interference pattern of our optical TES devices with and without anti-reflection coating and obtain the gap distance. We also obtain the absolute reflectivity of the Ti-TESs by correcting the effect of power splitter and circulator. Our copper block shrinks ~10 μm when cooled from room temperature down to 100 mK. The measured reflectivity is consistent with the simulation taking the dielectric mirror, Ti film and anti-reflection coating into account. In addition, we study the gap distance dependence of the system efficiency, and find that it is in good agreement with the measured reflectivity at 100 mK. These analyses are useful for further improvement of TES packaging.

DOI
10.1117/12.2603899

Related papers

Development of Titanium-Based Transition-Edge Single-Photon Detector

Wen Zhang, Yue Geng, Zheng Wang +7 more

Superconducting transition-edge sensors (TESs), working as single-photon detectors with high quantum efficiency, low dark count rate, and photon number resolving capability, have been successfully used in quantum information experiments as well as astronomical transient object observations. Aiming to achieve high count rate, we are developing titanium-based superconducting TES single-photon detectors with a critical temperature of ~300 mK. Ti-based TESs with active area from 10 × 10 μm to 40 × 40 μm are first fabricated on silicon substrate coated with SiOx. The fabricated TES devices show a thermal conductance scaling with the active area and an effective time constant of ~4 μs from pulsed laser diode illumination. In order to get high quantum efficiency, we further design and fabricate a 1550-nm optical cavity based on dielectric mirror and antireflection layer, and study its absorption with an IR spectrometer. Ti TES devices on the dielectric mirror are then fabricated and the superconducting transition is measured.

IEEE Transactions on Applied Superconductivity•Mar 19, 2019•19 citations

Optimizing Optical TESs for High-Efficiency Multimode Fiber Coupling

Federico Malnati, Greta Andrini, Hobey Garrone +6 more

Transition-Edge Sensors (TESs) are superconducting photon detectors offering high quantum efficiency, energy resolution, and photon-number discrimination, making them attractive for quantum sensing applications. We report on the design, fabrication, and characterization of a Ti/Au/Ti TES optimized for multimode fiber coupling in NV-center experiments. The device integrates a bi-layer anti-reflective coating optimized for 700 nm, the emission wavelength range of NV centers in which we are interested. Optical characterization in a cryogenic setup demonstrated an energy resolution below 2 eV and photon-number resolution capability. A dedicated calibration setup was used to evaluate the system detection efficiency (SDE), yielding$0.85 \pm 0.02$. These results confirm the suitability of large-area TESs for efficient multimode fiber coupling and highlight their potential for improving the performance of NV-center-based quantum sensing experiments.

IEEE Transactions on Applied Superconductivity•Mar 23, 2026•0 citations

Characterization of Optical Fast Transition-Edge Sensors With Optimized Fiber Coupling

L. Lolli, E. Taralli, M. Rajteri +2 more

Energy resolution (ΔE), recovery time (τeff), and quantum efficiency (QE) are some of the most important single photon-counting detector parameters. New applications in the quantum optics field place extreme demand on detector performances that go beyond the capabilities of established single-photon detectors. Unfortunately, it is hard to reach best results for all these parameters at the same time. Concerning transition-edge sensors (TESs) as single photon detectors, ΔEand τeffare directly and inversely proportional to the transition temperatureTc, respectively. Moreover, the geometrical optical coupling between illuminating fiber and detector, the device material and the characteristics of the optical cavity or the antireflection coating, drastically influence theQEand in some cases also the ΔE. Previous TESs fabricated by Istituto Nazionale di Ricerca Metrologica were characterized by very high energy resolution (0.18 eV) but high τeffand lowQE. In this work, we present a Ti/Au TES with higherTc(300 mK) that, using the optical alignment system implemented by AIST, shows an optimization of these important parameters, energy resolution of 0.26 eV, recovery time of 186 ns, and a quantum efficiency of 50% without using any optical structure deposited on the detector.

IEEE Transactions on Applied Superconductivity•Feb 20, 2013•25 citations

Development of High Detection Efficiency Titanium Transition-Edge Sensors for 1550 nm Single-Photon Detection

Xiaolong Xu, Peizhan Li, Carlo Pepe +10 more

Transition-edge sensors (TESs) have shown the capability of both energy resolution and resolving photon numbers. In this work, we present the fabrication and characterization of high detection efficiency Ti optical TESs with the critical temperatureTc= 213 mK and the photon-number resolving capability at telecommunication wavelength 1550 nm. The Ti superconducting film is prepared by a DC magnetron sputtering technique. An optical cavity comprised of 5-layers antireflection and 15-layers high-reflection Ta2O5/SiO2is enclosed with the Ti film by an ion beam assisted deposition method to improve detection efficiency, which brings the absorption of 99.74%. The energy resolution for the Ti TES with sensitive area 20 μm × 20 μm is 0.45 eV and the detection efficiency is 97% ± 1%.

IEEE Transactions on Applied Superconductivity•Jan 12, 2026•2 citations

Titanium TES based photon number resolving detectors with 1 MHz counting rate and 65% quantum efficiency

Daiji Fukuda, Go Fujii, Takayuki Numata +4 more

A transition edge sensor (TES) is one of superconducting photon detectors, which has a photon number resolving ability in light pulses. The TES device is a kind of calorimeters operated at an extremely low temperature, and the energy of the photons is measured as a resistance change in a superconducting transition region of the TES. The advantages of the TESs are an excellent energy resolution and a high quantum efficiency. However a response speed is limited due to slow thermal recovery time. To overcome this, we fabricated new TES devices which are based on a titanium superconductor. The critical temperature of our titanium films is around 410 mK, which greatly improves the thermal recovery time. The observed decay time constant of response signals to the light pulses is around several hundreds of ns, that make it possible to operate the devices at a counting rate over 1 MHz. The photon number resolving power is 0.35 eV(FWHM) for a 5 μm size device even at the high operating temperature. The system quantum efficiency is 65 % by embedding the TES films in an optical structure with a high reflection dielectric mirror and an anti-reflection coatings fabricated by an ion beam assisted sputtering method. These features are very promising for high speed photon number resolving applications in the quantum information field.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Dec 2, 2008•11 citations

Improvement of Ti-based Superconducting Transition Edge Sensors with Dielectric Mirror

Peng Li, Jinfeng Wang, S. C. Shi +8 more

We have improved the detection efficiency of Ti-based superconducting transition edge sensor(TES) with the integration of dielectric mirror at the operation wavelength of 1550 nm. The TES fabricated on the dielectric mirror is coupled to the optical fiber using back-side through-chip imaging. The measured effective response time is several μs and the detection efficiency is improved to 30%.

International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)•Sep 1, 2019•2 citations
Optical transition-edge sensor (TES) with high quantum efficiency, low dark count rate, and high energy resolution has been used in quantum information and communications. The gap distance between the fiber tip and TES has an influence on the TES performance. Here we measured the interference pattern of our optical TES devices with and without anti-reflection coating and obtain the gap distance. We also obtain the absolute reflectivity of the Ti-TESs by correcting the effect of power splitter and circulator. Our copper block shrinks ~10 μm when cooled from room temperature down to 100 mK. The measured reflectivity is consistent with the simulation taking the dielectric mirror, Ti film and anti-reflection coating into account. In addition, we study the gap distance dependence of the system efficiency, and find that it is in good agreement with the measured reflectivity at 100 mK. These analyses are useful for further improvement of TES packaging.
Superconducting transition-edge sensors (TESs), working as single-photon detectors with high quantum efficiency, low dark count rate, and photon number resolving capability, have been successfully used in quantum information experiments as well as astronomical transient object observations. Aiming to achieve high count rate, we are developing titanium-based superconducting TES single-photon detectors with a critical temperature of ~300 mK. Ti-based TESs with active area from 10 × 10 μm to 40 × 40 μm are first fabricated on silicon substrate coated with SiOx. The fabricated TES devices show a thermal conductance scaling with the active area and an effective time constant of ~4 μs from pulsed laser diode illumination. In order to get high quantum efficiency, we further design and fabricate a 1550-nm optical cavity based on dielectric mirror and antireflection layer, and study its absorption with an IR spectrometer. Ti TES devices on the dielectric mirror are then fabricated and the superconducting transition is measured.
Transition-Edge Sensors (TESs) are superconducting photon detectors offering high quantum efficiency, energy resolution, and photon-number discrimination, making them attractive for quantum sensing applications. We report on the design, fabrication, and characterization of a Ti/Au/Ti TES optimized for multimode fiber coupling in NV-center experiments. The device integrates a bi-layer anti-reflective coating optimized for 700 nm, the emission wavelength range of NV centers in which we are interested. Optical characterization in a cryogenic setup demonstrated an energy resolution below 2 eV and photon-number resolution capability. A dedicated calibration setup was used to evaluate the system detection efficiency (SDE), yielding0.85±0.020.85 \pm 0.020.85±0.02. These results confirm the suitability of large-area TESs for efficient multimode fiber coupling and highlight their potential for improving the performance of NV-center-based quantum sensing experiments.
Energy resolution (ΔE), recovery time (τeff), and quantum efficiency (QE) are some of the most important single photon-counting detector parameters. New applications in the quantum optics field place extreme demand on detector performances that go beyond the capabilities of established single-photon detectors. Unfortunately, it is hard to reach best results for all these parameters at the same time. Concerning transition-edge sensors (TESs) as single photon detectors, ΔEand τeffare directly and inversely proportional to the transition temperatureTc, respectively. Moreover, the geometrical optical coupling between illuminating fiber and detector, the device material and the characteristics of the optical cavity or the antireflection coating, drastically influence theQEand in some cases also the ΔE. Previous TESs fabricated by Istituto Nazionale di Ricerca Metrologica were characterized by very high energy resolution (0.18 eV) but high τeffand lowQE. In this work, we present a Ti/Au TES with higherTc(300 mK) that, using the optical alignment system implemented by AIST, shows an optimization of these important parameters, energy resolution of 0.26 eV, recovery time of 186 ns, and a quantum efficiency of 50% without using any optical structure deposited on the detector.
Transition-edge sensors (TESs) have shown the capability of both energy resolution and resolving photon numbers. In this work, we present the fabrication and characterization of high detection efficiency Ti optical TESs with the critical temperatureTc= 213 mK and the photon-number resolving capability at telecommunication wavelength 1550 nm. The Ti superconducting film is prepared by a DC magnetron sputtering technique. An optical cavity comprised of 5-layers antireflection and 15-layers high-reflection Ta2O5/SiO2is enclosed with the Ti film by an ion beam assisted deposition method to improve detection efficiency, which brings the absorption of 99.74%. The energy resolution for the Ti TES with sensitive area 20 μm × 20 μm is 0.45 eV and the detection efficiency is 97% ± 1%.
A transition edge sensor (TES) is one of superconducting photon detectors, which has a photon number resolving ability in light pulses. The TES device is a kind of calorimeters operated at an extremely low temperature, and the energy of the photons is measured as a resistance change in a superconducting transition region of the TES. The advantages of the TESs are an excellent energy resolution and a high quantum efficiency. However a response speed is limited due to slow thermal recovery time. To overcome this, we fabricated new TES devices which are based on a titanium superconductor. The critical temperature of our titanium films is around 410 mK, which greatly improves the thermal recovery time. The observed decay time constant of response signals to the light pulses is around several hundreds of ns, that make it possible to operate the devices at a counting rate over 1 MHz. The photon number resolving power is 0.35 eV(FWHM) for a 5 μm size device even at the high operating temperature. The system quantum efficiency is 65 % by embedding the TES films in an optical structure with a high reflection dielectric mirror and an anti-reflection coatings fabricated by an ion beam assisted sputtering method. These features are very promising for high speed photon number resolving applications in the quantum information field.