Low-Filling-Factor Superconducting Single Photon Detector with High System Detection Efficiency

TL;DR

This paper presents the design and fabrication of superconducting nanowire single-photon detectors with low filling factors that achieve high system detection efficiency and counting rates, supported by numerical simulations and systematic measurements.

Contribution

It introduces a novel approach to maintain high optical absorptance in SSPDs with low filling factors through optimized device design.

Findings

High SDE of 61-80% achieved in low filling factor SSPDs.

Numerical simulations confirm high optical absorptance at low filling factors.

The lowest filling factor device achieved a 69% SDE.

Abstract

We designed, fabricated, and measured superconducting nanowire single-photon detectors (SSPDs) with low filling factor which achieve high system detection efficiency (SDE) and counting rate simultaneously. Numerical simulation reveals that high optical absorptance is possible in SSPDs even for low filing factor by tuning the device design. The SDEs of fabricated 18-50% filling factor SSPDs were measured systematically, and all SSPDs showed high SDEs of 61-80% and the lowest 18% filling factor SSPD achieved a high SDE of 69%.