Counting near-infrared single-photons with 95% efficiency

Area of Science:

• Quantum Information Science
• Superconducting Detector Technology
• Photonics

Background:

• High-efficiency, low-noise single-photon detectors are crucial for quantum information applications.
• Superconducting transition-edge sensors (TESs) offer photon-number resolution but require stringent design optimization.

Purpose of the Study:

• To fabricate and evaluate a fiber-coupled, photon-number-resolving TES detector.
• To optimize the detector for absorption at 1550 and 1310 nm wavelengths.

Main Methods:

• Fabrication of a superconducting transition-edge sensor.
• Fiber coupling for optical input.
• Characterization of system detection efficiency at near-infrared wavelengths.

Main Results:

• The developed TES detector is optimized for 1550 and 1310 nm.
• Measured system detection efficiency at 1556 nm reached 95% ± 2%.
• This represents the highest reported system detection efficiency for a near-infrared single-photon detector.

Conclusions:

• The optimized fiber-coupled TES demonstrates state-of-the-art performance for single-photon detection.
• This advancement is significant for quantum information processing and communication.
• The high detection efficiency and photon-number resolution pave the way for more advanced quantum technologies.