NbTiN superconducting nanowire detectors for visible and telecom wavelengths single photon counting on Si3N4 photonic circuits

TL;DR

This paper presents NbTiN superconducting nanowire detectors integrated on Si3N4 photonic circuits capable of efficient single-photon detection across visible and telecom wavelengths, advancing integrated quantum optics.

Contribution

It introduces a novel on-chip integration of superconducting nanowire detectors with Si3N4 photonic circuits for broadband single-photon detection.

Findings

Successful detection of visible photons

Efficient infrared photon detection

Integrated on-chip quantum photonic platform

Abstract

We demonstrate niobium titanium nitride superconducting nanowires patterned on stoichiometric silicon nitride waveguides for detecting visible and infrared photons. The use of silicon nitride on insulator on silicon substrates allows us to simultaneously realize photonic circuits for visible and infrared light and integrate them with nanowire detectors directly on-chip. By implementing a traveling wave detector geometry in this material platform, we achieve efficient single photon detection for both wavelength regimes. Our detectors are an ideal match for integrated quantum optics as they provide crucial functionality on a wideband transparent waveguide material.