7 research outputs found
Photon-number resolving detector based on a series array of superconducting nanowires
We present the experimental demonstration of a superconducting photon number
resolving detector. It is based on the series connection of N superconducting
nanowires, each connected in parallel to an integrated resistor. The device
provides a single voltage readout, proportional to the number of photons
absorbed in distinct nanowires. Clearly separated output levels corresponding
to the detection of n=1-4 photons are observed in a 4-element detector
fabricated from an NbN film on GaAs substrate, with a single-photon system
quantum efficiency of 2.6% at the wavelength of 1300nm. The series-nanowire
structure is promising in view of its scalability to large photon numbers and
high efficiencies.Comment: 12 pages, 6 figure
Ultrasensitive N-photon interferometric autocorrelator
We demonstrate a novel method to measure the Nth-order (N=1, 2, 3, 4)
interferometric autocorrelation with high sensitivity and temporal resolution.
It is based on the combination of linear absorption and nonlinear detection in
a superconducting nanodetector, providing much higher efficiency than methods
based on all-optical nonlinearities. Its temporal resolution is only limited by
the quasi-particle energy relaxation time, which is directly measured to be in
the 20 ps range for the NbN films used in this work. We present a general model
of interferometric autocorrelation with these nonlinear detectors and discuss
the comparison with other approaches and possible improvements
Superconducting series nanowire detector counting up to twelve photons
We demonstrate a superconducting photon-number-resolving detector capable of
resolving up to twelve photons at telecommunication wavelengths. It is based on
a series array of twelve superconducting NbN nanowire elements, each connected
in parallel with an integrated resistor. The photon-induced voltage signals
from the twelve elements are summed up into a single readout pulse with a
height proportional to the detected photon number. Thirteen distinct output
levels corresponding to the detection of n=0-12 photons are observed
experimentally. A detailed analysis of the excess noise shows the potential of
scaling to an even larger dynamic range.Comment: 13 page
Waveguide single-photon detectors for integrated quantum photonic circuits
The generation, manipulation and detection of quantum bits (qubits) encoded
on single photons is at the heart of quantum communication and optical quantum
information processing. The combination of single-photon sources, passive
optical circuits and single-photon detectors enables quantum repeaters and
qubit amplifiers, and also forms the basis of all-optical quantum gates and of
linear-optics quantum computing. However, the monolithic integration of
sources, waveguides and detectors on the same chip, as needed for scaling to
meaningful number of qubits, is very challenging, and previous work on quantum
photonic circuits has used external sources and detectors. Here we propose an
approach to a fully-integrated quantum photonic circuit on a semiconductor
chip, and demonstrate a key component of such circuit, a waveguide
single-photon detector. Our detectors, based on superconducting nanowires on
GaAs ridge waveguides, provide high efficiency (20%) at telecom wavelengths,
high timing accuracy (60 ps), response time in the ns range, and are fully
compatible with the integration of single-photon sources, passive networks and
modulators.Comment: 11 pages, 4 figure
Multiphoton detection in superconducting nanowires: Nonlinear optics in the detector
A Nth-order (N=1, 2, 3, 4, 5, 6) interferometric autocorrelator based on superconducting nanodetectors is presented. It provides much higher sensitivity as compared to the conventional autocorrelators using all-optical nonlinearities and a temporal resolution of about 20 ps, which is limited by the quasi-particle energy relaxation time in the superconducting films. A semiclassical model is introduced to explain the nonlinear photodetection process. A comparison of sensitivity to conventional autocorrelators is also presented. © 2013 SPIE
Ultrasensitive N-Photon interferometric autocoreelator
We demonstrate a novel method to measure Nth-order (N=1,2,3,4) interferometric autocorrelation with high sensitivity and temporal resolution. It is based on the combination of linear absorption and nonlinear detection in a superconducting nanodetector, providing much higher efficiency than methods based on all-optical nonlinearities. Its temporal resolution is only limited by the quasiparticle energy relaxation time, which is directly measured to be in the 20 ps range for the NbN films used in this work. We present a general model of interferometric autocorrelation with these nonlinear detectors and discuss the comparison with other approaches and possible improvements