Auniontech QE85% Superconducting Nanowire Single-Photon Detector (SNSPD)

Overview

The Auniontech QE85% Superconducting Nanowire Single-Photon Detector (SNSPD) is a cryogenically operated photodetector engineered for ultra-low-noise, time-resolved photon counting across the visible to mid-infrared spectrum (600–2300 nm). Based on NbN or MoSi superconducting nanowire technology, it operates at <2.5 K—typically integrated with closed-cycle or liquid helium cryocoolers—to exploit the sharp superconducting-to-normal transition triggered by single-photon absorption. This physical mechanism enables intrinsic photon-number resolution (PNR)-capable operation in multi-pixel configurations, sub-45 ps timing jitter, and near-zero afterpulsing—critical for quantum optical experiments requiring high-fidelity temporal correlation and minimal false detection events. Unlike avalanche photodiodes (APDs), SNSPDs exhibit no gain noise, enabling deterministic photon detection with quantum efficiency exceeding 85% across a broad spectral band, making them the detector of choice for demanding applications in quantum information science, time-correlated single-photon counting (TCSPC), and low-flux infrared spectroscopy.

Key Features

• Quantum efficiency ≥85% across 600–2300 nm—peak performance optimized for telecom O-, E-, S-, C-, and L-bands as well as visible quantum optics wavelengths
• Ultra-low dark count rate: ≤10 cps standard; optionally down to ≤0.01 cps with enhanced thermal filtering and bias stabilization
• Timing jitter ≤45 ps full-width-at-half-maximum (FWHM); selectable ≤20 ps variant for ultrafast coincidence measurements
• Maximum sustained count rate >20 MHz per channel—enabled by fast nanowire recovery dynamics and low-capacitance readout architecture
• Scalable multi-channel configuration: 1–8 independently addressable, fiber-coupled detection units in a single cryogenic package
• Fiber input via industry-standard SMF-28e single-mode fiber with FC/APC or FC/PC termination options
• Flexible electrical output: TTL, ECL, or LVDS logic levels—configurable per channel to interface with time-tagging electronics (e.g., PicoQuant HydraHarp, IDQ ID900)
• USB-based control interface with native LabVIEW drivers, supporting real-time bias tuning, temperature monitoring, and channel synchronization

Sample Compatibility & Compliance

The QE85% SNSPD is designed for integration into vacuum-compatible, vibration-isolated cryogenic systems operating below 2.5 K. It complies with ISO/IEC 17025 traceability requirements when calibrated using NIST-traceable transfer standards (e.g., calibrated photodiode + tunable laser source). Its passive, non-amplified detection architecture ensures immunity to electromagnetic interference (EMI) and eliminates voltage-dependent gain drift—key for GLP-compliant TCSPC setups and long-duration quantum key distribution (QKD) field trials. The device meets mechanical and thermal specifications outlined in IEC 61326-1 (EMC for laboratory equipment) and supports audit-ready metadata logging—including timestamped bias voltage, stage temperature, and raw pulse counts—for FDA 21 CFR Part 11–aligned data integrity workflows.

Software & Data Management

Auniontech provides a cross-platform SDK (Windows/Linux/macOS) with C/C++, Python, and MATLAB bindings, enabling full programmability of bias current, channel enable/disable states, and output logic selection. The included acquisition software supports synchronized multi-channel histogramming, live jitter analysis (using Allan deviation plots), and export of time-stamped event lists in HDF5 or ASCII formats compliant with the Photonics Standards Consortium (PSC) metadata schema. All firmware updates are digitally signed and version-locked to prevent unauthorized modification—supporting GMP-aligned change control documentation. Audit trails record all user-initiated parameter changes with timestamps and operator IDs, satisfying ALCOA+ principles for regulated environments.

Applications

• Photonic quantum computing: Bell-state measurement, boson sampling, and linear optical quantum circuits requiring high-efficiency, low-jitter detection
• Quantum key distribution (QKD): Decoy-state BB84 and measurement-device-independent (MDI) protocols demanding sub-10 cps dark counts and GHz-level synchronization capability
• Time-resolved fluorescence spectroscopy: TCSPC of single-molecule emitters, quantum dots, and triplet-state oxygen with picosecond temporal resolution
• Free-space optical communication: Deep-space and atmospheric links leveraging high NIR sensitivity and polarization-insensitive response
• LIDAR and time-of-flight imaging: Single-photon depth mapping under extreme low-light conditions (e.g., nighttime satellite tracking)
• Ballistic photon detection in turbid media: Early-arrival photon discrimination for biomedical diffuse optical tomography
• On-chip quantum optics: Integration with silicon nitride or lithium niobate photonic integrated circuits (PICs) via edge coupling
• Single-plasmon and single-exciton detection in nanophotonic cavities and 2D materials
• CMOS failure analysis: Picosecond-resolution emission microscopy (PEM) for dynamic fault isolation in advanced nodes

FAQ

What cooling infrastructure is required to operate this SNSPD?
The detector must be mounted in a cryostat maintaining a base temperature ≤2.5 K—typically achieved using a two-stage closed-cycle refrigerator (e.g., BlueFors LD or Janis ST-100) or liquid helium bath. Athermalization of the fiber feedthrough and RF shielding are mandatory.
Is polarization sensitivity compensated in the standard configuration?
Standard devices exhibit <15% polarization-dependent efficiency variation (PDE) across the 600–2300 nm band; polarization-insensitive variants with sub-3% PDE are available upon request.
Can multiple channels be time-synchronized to within 10 ps?
Yes—hardware-triggered channel alignment via common clock distribution yields inter-channel timing skew <5 ps RMS when using matched-length coaxial cabling and differential signaling (LVDS/ECL).
Does the system support photon-number-resolving (PNR) capability?
While single-pixel elements are intrinsically binary, 8-channel arrays can provide coarse PNR through spatial multiplexing; true PNR operation requires custom multi-nanowire meander designs not included in the standard QE85% model.
What calibration certificates are supplied with shipment?
Each unit ships with a factory calibration report listing measured QE at five wavelengths (635, 850, 1310, 1550, and 2000 nm), dark count histogram, jitter FWHM, and recovery time—all traceable to PTB/NIST reference standards.