Multimode Fiber Coupled Superconducting Nanowire Single Photon Detectors with High Detection Efficiency and Time Resolution

TL;DR

This paper demonstrates high-efficiency, high-time-resolution superconducting nanowire single photon detectors coupled to multimode fibers, addressing polarization effects and enabling advanced quantum and bio-optic applications.

Contribution

It introduces a method to optimize multimode fiber coupled SNSPDs for high efficiency and time resolution, including polarization management and large detector fabrication.

Findings

Achieved >80% system efficiency

Achieved <20 ps time resolution

Demonstrated performance across multiple wavelengths

Abstract

In the past decade superconducting nanowire single photon detectors (SNSPDs) have gradually become an indispensable part of any demanding quantum optics experiment. Until now, most SNSPDs are coupled to single-mode fibers. SNSPDs coupled to multimode fibers have shown promising efficiencies but are yet to achieve high time resolution. For a number of applications ranging from quantum nano-photonics to bio-optics, high efficiency and high time-resolution are desired at the same time. In this paper, we demonstrate the role of polarization on the efficiency of multi-mode fiber coupled detectors, and show how it can be addressed. We fabricated high performance 20, 25 and 50{\mu}m diameter detectors targeted for visible, near infrared, and telecom wavelengths. A custom-built setup was used to simulate realistic experiments with randomized modes in the fiber. We simultaneously achieved system efficiency >80% and time resolution <20 ps and made large detectors that offer outstanding performances.