Waveguide integrated low noise NbTiN nanowire single-photon detectors with milli-Hz dark count rate

TL;DR

This paper reports the development of NbTiN superconducting nanowire single-photon detectors integrated on Si3N4 waveguides, achieving milli-Hz dark count rates, high detection efficiency, and low timing jitter for quantum photonics applications.

Contribution

It introduces ultra-low noise NbTiN nanowire detectors with systematic design optimization and demonstrates milli-Hz dark count rates across the entire operating range.

Findings

Milli-Hz dark count rates achieved

High detection efficiency in integrated detectors

Low timing jitter demonstrated

Abstract

Superconducting nanowire single-photon detectors are an ideal match for integrated quantum photonic circuits due to their high detection efficiency for telecom wavelength photons. Quantum optical technology also requires single-photon detection with low dark count rate and high timing accuracy. Here we present very low noise superconducting nanowire single-photon detectors based on NbTiN thin films patterned directly on top of Si3N4 waveguides. We systematically investigate a large variety of detector designs and characterize their detection noise performance. Milli-Hz dark count rates are demonstrated over the entire operating range of the nanowire detectors which also feature low timing jitter. The ultra-low dark count rate, in combination with the high detection efficiency inherent to our traveling wave detector geometry, gives rise to a measured noise equivalent power at the 10^(-20) W/Hz^(1/2) level.