Spectrally resolved single-photon imaging with hybrid superconducting - nanophotonic circuits

TL;DR

This paper presents a compact, scalable, waveguide-integrated single-photon spectrometer using hybrid superconducting-nanophotonic circuits, enabling spectral discrimination and imaging at multiple wavelengths with high temporal resolution.

Contribution

It introduces a novel integrated spectrometer that combines superconducting detectors with nanophotonics for parallel multi-wavelength single-photon detection.

Findings

Demonstrated multi-wavelength detection at telecommunication and visible ranges.

Achieved temporal resolution below 50 ps and dark count rates under 10 Hz.

Enabled spectral imaging of silicon vacancy centers in diamond nanoclusters.

Abstract

The detection of individual photons is an inherently binary mechanism, revealing either their absence or presence while concealing their spectral information. For multi-color imaging techniques, such as single photon spectroscopy, fluorescence resonance energy transfer microscopy and fluorescence correlation spectroscopy, wavelength discrimination is essential and mandates spectral separation prior to detection. Here, we adopt an approach borrowed from quantum photonic integration to realize a compact and scalable waveguide-integrated single-photon spectrometer capable of parallel detection on multiple wavelength channels, with temporal resolution below 50 ps and dark count rates below 10 Hz. We demonstrate multi-detector devices for telecommunication and visible wavelengths and showcase their performance by imaging silicon vacancy color centers in diamond nanoclusters. The fully integrated hybrid superconducting-nanophotonic circuits enable simultaneous spectroscopy and lifetime mapping for correlative imaging and provide the ingredients for quantum wavelength division multiplexing on a chip.