Demonstrating sub-3 ps temporal resolution in a superconducting nanowire single-photon detector

TL;DR

This paper reports achieving a sub-3 picosecond temporal resolution in superconducting nanowire single-photon detectors, significantly improving their performance for applications in quantum communication, biomedical imaging, and optical sensing.

Contribution

The authors demonstrate a novel SNSPD with a temporal resolution below 3 ps, advancing the state-of-the-art in single-photon detection speed and precision.

Findings

Achieved 2.7 ps resolution at 400 nm

Achieved 4.6 ps resolution at 1550 nm

Photon-energy dependence affects temporal resolution

Abstract

Improving the temporal resolution of single photon detectors has an impact on many applications, such as increased data rates and transmission distances for both classical and quantum optical communication systems, higher spatial resolution in laser ranging and observation of shorter-lived fluorophores in biomedical imaging. In recent years, superconducting nanowire single-photon detectors (SNSPDs) have emerged as the highest efficiency time-resolving single-photon counting detectors available in the near infrared. As the detection mechanism in SNSPDs occurs on picosecond time scales, SNSPDs have been demonstrated with exquisite temporal resolution below 15 ps. We reduce this value to 2.7$\pm$0.2 ps at 400 nm and 4.6$\pm$0.2 ps at 1550 nm, using a specialized niobium nitride (NbN) SNSPD. The observed photon-energy dependence of the temporal resolution and detection latency suggests that intrinsic effects make a significant contribution.