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

Conference on Lasers and Electro-Optics

Polarization independence in superconducting microwire single-photon detectors

Dileep V. Reddy, Negar Otrooshi, Sae Woo Nam, Richard P. Mirin, Varun Boehm Verma

Published Jan 1, 2022• 0 citations
Publisher

Abstract

Micrometer-scale superconducting wires can detect single photons at near-infrared wavelengths. We employ a novel meander geometry to fabricate high-fill factor microwire devices with low polarization sensitivity (1.02 ± 0.008) and high efficiency 93%) across a 40 nm bandwidth centered at 1550 nm.
DOI
10.1364/cleo_si.2022.sm3k.2

Related papers

Broadband polarization insensitivity and high detection efficiency in high-fill-factor superconducting microwire single-photon detectors

Dileep V. Reddy, Negar Otrooshi, Sae Woo Nam +2 more

Single-photon detection via absorption in current-biased nanoscale superconducting structures has become a preferred technology in quantum optics and related fields. Single-mode fiber packaged devices have seen new records set in detection efficiency, timing jitter, recovery times, and the largest sustainable count rates. The popular approaches to decreasing polarization sensitivity have resorted to the deposition of a high-index dielectric layer in between the nanowires or the introduction of geometrically symmetric nanowire meanders, such as spirals and fractals, in the active area. The former method yields limited success, while constraints on bending radii, and by extension fill factors in the latter limits their maximum efficiency. The discovery of single-photon sensitivity in micrometer-scale superconducting wires enables novel meander patterns with no effective upper limit on the fill factor. This work demonstrates simultaneous low-polarization sensitivity (1.02 ± 0.008) and high detection efficiency (>91.8% to better than one standard deviation at 2 × 105 counts/s) across a 40 nm bandwidth centered at 1550 nm in 0.51 μm wide microwire devices made of silicon-rich tungsten silicide, sporting a new candelabra-style meander pattern with a fill factor of 0.91 in the active area. These devices boasted efficiencies of 96.5%–96.9% ± 0.5% at 1 × 105 counts/s for 1550 nm light.

arXiv:2202.05942•APL Photonics•May 1, 2022•32 citations

Superconducting microwire detectors based on WSi with single-photon sensitivity in the near-infrared

Jeff Chiles, Sonia Mary Buckley, Adriana E. Lita +7 more

We report on the fabrication and characterization of single-photon-sensitive WSi superconducting detectors with wire widths from 1 μm to 3 μm. The devices achieve the saturated internal detection efficiency at a wavelength of 1.55 μm and exhibit maximum count rates in excess of 105 s−1. We also investigate the material properties of the silicon-rich WSi films used for these devices. We find that many devices with active lengths of several hundred micrometers exhibit critical currents in excess of 50% of the depairing current. A meandered detector with a 2.0 μm wire width is demonstrated over a surface area of 362 × 362 μm2, showcasing the material and device quality achieved.

arXiv:2002.12858•Applied Physics Letters•Jun 15, 2020•72 citations

Spiral superconducting nanowire single-photon detector with efficiency over 50% at 1550 nm wavelength

Jia Huang, Weijun Zhang, Lixing You +8 more

Abstract Superconducting nanowire single-photon detectors (SNSPDs) are widely used for the detection of visible and near-infrared single photons. Due to the nature of the polarization sensitive absorption of the nanowire, the detection efficiency (DE) of the meander SNSPD is polarization sensitive. In order to obtain a polarization-insensitive device with high DE, we fabricated NbN SNSPDs with spiral structure, which were embedded into an optical cavity. No meaningful current crowding effect was observed in the spiral SNSPDs. The spiral SNSPD showed a maximal system detection efficiency of 52.5% at 1550 nm with a dark count rate of 100 Hz and a polarization extinction ratio of 1.04, due to the combination of a spiral geometry and an optical cavity.

Superconductor Science and Technology•Apr 12, 2017•36 citations

Design of a polarization-insensitive superconducting nanowire single photon detector with high detection efficiency

Fan Zheng, Ruiying Xu, Guanghao Zhu +5 more

Superconducting nanowire single photon detectors (SNSPDs) deliver superior performance over their competitors in the near-infrared regime. However, these detectors have an intrinsic polarization dependence on the incident wave because of their one-dimensional meander structure. In this paper, we propose an approach to eliminate the polarization sensitivity of SNSPDs by using near-field optics to increase the absorption of SNSPDs under transverse magnetic (TM) illumination. In addition, an optical cavity is added to our SNSPD to obtain nearly perfect absorption of the incident wave. Numerical simulations show that the maximum absorption of a designed SNSPD can reach 96% at 1550 nm, and indicate that the absorption difference between transverse electric (TE) and TM polarization is less than 0.5% across a wavelength window of 300 nm. Our work provides the first demonstration of the possibility of designing a polarization-insensitive and highly efficient SNSPD without performing device symmetry improvements.

Scientific Reports•Mar 7, 2016•37 citations

Design of efficient superconducting nanowire single photon detectors for near-infrared wavelengths

M. J. A. de Dood

Superconducting single photon detectors consist of a narrow and thin wire of superconductor and can detect single photons with high efficiency and high speed. Simultaneous optimization of the detection efficiency and detector response time is difficult because the response time is set by the dimensions of the wire (cross section and length) while the detection efficiency is determined by both the internal detection mechanism and the dimensions of the wire. Wider and shorter wires are easier to fabricate, are more robust and lead to shorter detector reset time, but are generally less efficient. Experiments employing detector tomography provide important insights into the photon detection mechanism and indicate a detection mechanism where the edges of the wire are more efficient. This leads to a position dependent local detection efficiency that can be explained in the context of a photon-assisted-vortex-entry model and predicts an optimum wire width ~70 nm. A 50 nm wide silicon nanowire deposited on top of a 150 nm wide NbN nanowire directs light at 1550 nm wavelength to the edges and improves both the total absorption efficiency and the internal detection efficiency of the wire. The total absorption efficiency can be enhanced by 30% while the internal detection efficiency is increased by 70%. Assuming that the wire covers a similar area the detector response time is reduced 4-fold compared to the standard design using a 70 nm wide wire.

Advanced Photon Counting Techniques•May 14, 2018•0 citations

Mid-infrared characterization of NbTiN superconducting nanowire single-photon detectors on silicon-on-insulator

Adan Azem, D. Morozov, Daniel Kuznesof +4 more

Superconducting nanowire single-photon detectors are widely used for detecting individual photons across various wavelengths from ultraviolet to near-infrared range. Recently, there has been increasing interest in enhancing their sensitivity to single photons in the mid-infrared spectrum, driven by applications in quantum communication, spectroscopy, and astrophysics. Here, we present our efforts to expand the spectral detection capabilities of U-shaped NbTiN-based superconducting nanowire single-photon detectors, fabricated in a 2-wire configuration on a silicon-on-insulator substrate, into the mid-infrared range. We demonstrate saturated internal detection efficiency extending up to a wavelength of 3.5 μm for a 5 nm thick and 50 nm wide NbTiN nanowire with a dark count rate less than 10 counts per second at 0.9 K and a rapid recovery time of 4.3 ns. The detectors are engineered for integration on waveguides in a silicon-on-insulator platform for compact, multi-channel device applications.

arXiv:2408.15959•Applied Physics Letters•Nov 18, 2024•12 citations
Single-photon detection via absorption in current-biased nanoscale superconducting structures has become a preferred technology in quantum optics and related fields. Single-mode fiber packaged devices have seen new records set in detection efficiency, timing jitter, recovery times, and the largest sustainable count rates. The popular approaches to decreasing polarization sensitivity have resorted to the deposition of a high-index dielectric layer in between the nanowires or the introduction of geometrically symmetric nanowire meanders, such as spirals and fractals, in the active area. The former method yields limited success, while constraints on bending radii, and by extension fill factors in the latter limits their maximum efficiency. The discovery of single-photon sensitivity in micrometer-scale superconducting wires enables novel meander patterns with no effective upper limit on the fill factor. This work demonstrates simultaneous low-polarization sensitivity (1.02 ± 0.008) and high detection efficiency (>91.8% to better than one standard deviation at 2 × 105 counts/s) across a 40 nm bandwidth centered at 1550 nm in 0.51 μm wide microwire devices made of silicon-rich tungsten silicide, sporting a new candelabra-style meander pattern with a fill factor of 0.91 in the active area. These devices boasted efficiencies of 96.5%–96.9% ± 0.5% at 1 × 105 counts/s for 1550 nm light.
We report on the fabrication and characterization of single-photon-sensitive WSi superconducting detectors with wire widths from 1 μm to 3 μm. The devices achieve the saturated internal detection efficiency at a wavelength of 1.55 μm and exhibit maximum count rates in excess of 105 s−1. We also investigate the material properties of the silicon-rich WSi films used for these devices. We find that many devices with active lengths of several hundred micrometers exhibit critical currents in excess of 50% of the depairing current. A meandered detector with a 2.0 μm wire width is demonstrated over a surface area of 362 × 362 μm2, showcasing the material and device quality achieved.
Abstract Superconducting nanowire single-photon detectors (SNSPDs) are widely used for the detection of visible and near-infrared single photons. Due to the nature of the polarization sensitive absorption of the nanowire, the detection efficiency (DE) of the meander SNSPD is polarization sensitive. In order to obtain a polarization-insensitive device with high DE, we fabricated NbN SNSPDs with spiral structure, which were embedded into an optical cavity. No meaningful current crowding effect was observed in the spiral SNSPDs. The spiral SNSPD showed a maximal system detection efficiency of 52.5% at 1550 nm with a dark count rate of 100 Hz and a polarization extinction ratio of 1.04, due to the combination of a spiral geometry and an optical cavity.
Superconducting nanowire single photon detectors (SNSPDs) deliver superior performance over their competitors in the near-infrared regime. However, these detectors have an intrinsic polarization dependence on the incident wave because of their one-dimensional meander structure. In this paper, we propose an approach to eliminate the polarization sensitivity of SNSPDs by using near-field optics to increase the absorption of SNSPDs under transverse magnetic (TM) illumination. In addition, an optical cavity is added to our SNSPD to obtain nearly perfect absorption of the incident wave. Numerical simulations show that the maximum absorption of a designed SNSPD can reach 96% at 1550 nm, and indicate that the absorption difference between transverse electric (TE) and TM polarization is less than 0.5% across a wavelength window of 300 nm. Our work provides the first demonstration of the possibility of designing a polarization-insensitive and highly efficient SNSPD without performing device symmetry improvements.
Superconducting single photon detectors consist of a narrow and thin wire of superconductor and can detect single photons with high efficiency and high speed. Simultaneous optimization of the detection efficiency and detector response time is difficult because the response time is set by the dimensions of the wire (cross section and length) while the detection efficiency is determined by both the internal detection mechanism and the dimensions of the wire. Wider and shorter wires are easier to fabricate, are more robust and lead to shorter detector reset time, but are generally less efficient. Experiments employing detector tomography provide important insights into the photon detection mechanism and indicate a detection mechanism where the edges of the wire are more efficient. This leads to a position dependent local detection efficiency that can be explained in the context of a photon-assisted-vortex-entry model and predicts an optimum wire width ~70 nm. A 50 nm wide silicon nanowire deposited on top of a 150 nm wide NbN nanowire directs light at 1550 nm wavelength to the edges and improves both the total absorption efficiency and the internal detection efficiency of the wire. The total absorption efficiency can be enhanced by 30% while the internal detection efficiency is increased by 70%. Assuming that the wire covers a similar area the detector response time is reduced 4-fold compared to the standard design using a 70 nm wide wire.
Superconducting nanowire single-photon detectors are widely used for detecting individual photons across various wavelengths from ultraviolet to near-infrared range. Recently, there has been increasing interest in enhancing their sensitivity to single photons in the mid-infrared spectrum, driven by applications in quantum communication, spectroscopy, and astrophysics. Here, we present our efforts to expand the spectral detection capabilities of U-shaped NbTiN-based superconducting nanowire single-photon detectors, fabricated in a 2-wire configuration on a silicon-on-insulator substrate, into the mid-infrared range. We demonstrate saturated internal detection efficiency extending up to a wavelength of 3.5 μm for a 5 nm thick and 50 nm wide NbTiN nanowire with a dark count rate less than 10 counts per second at 0.9 K and a rapid recovery time of 4.3 ns. The detectors are engineered for integration on waveguides in a silicon-on-insulator platform for compact, multi-channel device applications.