18 research outputs found
Free Running Single Photon Detection based on a negative feedback InGaAs APD
InGaAs/InP-based semiconductor avalanche photodiode are usually employed for
single-photon counting at telecom wavelength. However they are affected by
afterpulsing which limits the diode performance. Recently, Princeton Lightwave
has commercialised a diode integrating monolithically a feedback resistor. This
solution effectively quenches the avalanche and drastically reduces
afterpulsing. Here, we report the development and characterization of a
detector module based on this diode, implementing an active hold-off circuit
which further reduces the afterpulsing and notably improves the detector
performances. We demonstrate free-running operation with 600 Hz dark count rate
at 10% detection efficiency. We also improved the standard double-window
technique for the afterpulsing characterization. Our algorithm implemented by a
FPGA allows to put the APD in a well-defined initial condition and to measure
the impact of the higher order afterpulses.Comment: 18 pages, 15 figures. Submitted to Journal of Modern Optic
High Speed and High Efficiency Travelling Wave Single-Photon Detectors Embedded in Nanophotonic Circuits
Ultrafast, high quantum efficiency single photon detectors are among the most
sought-after elements in modern quantum optics and quantum communication. High
photon detection efficiency is essential for scalable measurement-based quantum
computation, quantum key distribution, and loophole-free Bell experiments.
However, imperfect modal matching and finite photon absorption rates have
usually limited the maximum attainable detection efficiency of single photon
detectors. Here we demonstrate a superconducting nanowire detector atop
nanophotonic waveguides which allows us to drastically increase the absorption
length for incoming photons. When operating the detectors close to the critical
current we achieve high on-chip single photon detection efficiency up to 91% at
telecom wavelengths, with uncertainty dictated by the variation of the
waveguide photon flux. We also observe remarkably low dark count rates without
significant compromise of detection efficiency. Furthermore, our detectors are
fully embedded in a scalable silicon photonic circuit and provide ultrashort
timing jitter of 18ps. Exploiting this high temporal resolution we demonstrate
ballistic photon transport in silicon ring resonators. The direct
implementation of such a detector with high quantum efficiency, high detection
speed and low jitter time on chip overcomes a major barrier in integrated
quantum photonics
Superconducting single photon detectors integrated with diamond nanophotonic circuits
Photonic quantum technologies promise to repeat the success of integrated
nanophotonic circuits in non-classical applications. Using linear optical
elements, quantum optical computations can be performed with integrated optical
circuits and thus allow for overcoming existing limitations in terms of
scalability. Besides passive optical devices for realizing photonic quantum
gates, active elements such as single photon sources and single photon
detectors are essential ingredients for future optical quantum circuits.
Material systems which allow for the monolithic integration of all components
are particularly attractive, including III-V semiconductors, silicon and also
diamond. Here we demonstrate nanophotonic integrated circuits made from high
quality polycrystalline diamond thin films in combination with on-chip single
photon detectors. Using superconducting nanowires coupled evanescently to
travelling waves we achieve high detection efficiencies up to 66 % combined
with low dark count rates and timing resolution of 190 ps. Our devices are
fully scalable and hold promise for functional diamond photonic quantum
devices.Comment: 28 pages, 5 figure