Article

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

Department of Electrical Engineering, Yale University, New Haven, Connecticut, 06511, United States.
Scientific Reports (Impact Factor: 5.08). 05/2013; 3:1893. DOI: 10.1038/srep01893
Source: PubMed

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 travelling wave detector geometry, gives rise to a measured noise equivalent power at the 10(-20) W/Hz(1/2) level.

0 Bookmarks
·
113 Views
• Source
##### Article: Waveguide Integrated Superconducting Single Photon Detectors Implemented as Coherent Perfect Absorbers
[Hide abstract]
ABSTRACT: At the core of an ideal single photon detector is an active material that ideally absorbs and converts photons to discriminable electronic signals. A large active material volume favours high-efficiency absorption, but often at the expense of conversion efficiency, noise, speed and timing accuracy. The present work demonstrates how the concept of coherent perfect absorption can be used to relax this trade-off for a waveguide-integrated superconducting nanowire single photon detector. A very short (8.5$\mu$m long) and narrow (8$\times$35nm$^2$) U-shaped NbTiN nanowire atop a silicon-on-insulator waveguide is turned into a perfect absorber by etching an asymmetric nanobeam cavity around it. At 2.05K, the detectors show $\sim$96$\pm$12% on-chip quantum efficiency for 1545nm photons with an intrinsic dark count rate $<$0.1Hz. The estimated timing jitter is $\sim$53ps full-width at half-maximum and the reset time is $<$7ns, both extrinsically limited by readout electronics. This architecture is capable of pushing ultra-compact detector performance to ideal limits, and so promises to find a myriad of applications in quantum optics.
09/2014;
• Source
##### Article: Temperature dependence of niobium superconducting nanowire single-photon detectors in He-3 cryocooler
[Hide abstract]
ABSTRACT: Performances of superconducting nanowire single-photon detectors (SNSPDs) based on low T C materials strongly depend on the operating temperatures. We have fabricated infrared-sensitive niobium SNSPDs based on doped niobium (Nb*) films and measured them in He-3 cryocooler. The critical current approaches to the de-pairing current at 0.3 K. Therefore, with the decrease in temperatures, we have observed a monotonous increase of count rate at the wavelength of 1,521 nm and exponential decrease of dark count rate at all bias currents. The possible origin of dark counts for doped Nb devices is also discussed.
Chinese Science Bulletin 10/2014; 59(28). · 1.37 Impact Factor
• Source
##### Article: Waveguide Nanowire Superconducting Single-Photon Detectors Fabricated on GaAs and the Study of Their Optical Properties
[Hide abstract]
ABSTRACT: Quantum photonic integration is one of the leading approaches for enabling the implementation of quantum simulation and computing at the scale of tens to hundreds of photons. Quantum photonic integrated circuits require the monolithic integration of single-photon sources and passive circuit elements, such as waveguides and couplers, with single-photon detectors. A promising approach for on-chip single-photon detection is the use of superconducting nanowires on top of semiconductor waveguides. Here, we present state-of-the-art NbN films on GaAs for the realization of waveguide superconducting single-photon detectors, suitable for integration with sources and linear optical circuits. Based on the measured optical properties, we propose a new design which allows high absorptance for short nanowires in order to increase the integration density in a quantum photonic chip. Finally, we review recent results on integrated single-photon and photon-number-resolving detectors, and integrated autocorrelators.
IEEE Journal of Selected Topics in Quantum Electronics 03/2015; 21:3800210. · 3.47 Impact Factor