98 research outputs found
A novel active quenching circuit for single photon detection with Geiger mode avalanche photodiodes
In this paper we present a novel construction of an active quenching circuit
intended for single photon detection. For purpose of evaluation, we have
combined this circuit with a standard avalanche photodiode C30902S to form a
single photon detector. A series of measurements, presented here, show that
this single photon detector has a dead time of less than 40ns, maximum random
counting frequency of over 14MHz, low after pulsing, detection efficiency of
over 20% and a good noise performance. This simple and robust active quenching
circuit can be built from of-the-shelf electronic components and needs no
complicated adjustments.Comment: 9 pages, 13 figures, 15 reference
Characterization of A Novel Avalanche Photodiode for Single Photon Detection in VIS-NIR Range
In this work we investigate operation in the Geiger mode of the new single
photon avalanche photo diode (SPAD) SAP500 manufactured by Laser Components.
This SPAD is sensitive in the range 400-1000nm and has a conventional
reach-through structure which ensures good quantum efficiency at the long end
of the spectrum. By use of passive and active quenching schemes we investigate
detection efficiency, timing jitter, dark counts, afterpulsing, gain and other
important parameters and compare them to the "standard" low noise SPAD C30902SH
from Perkin Elmer. We conclude that SAP500 offers better combination of
detection efficiency, low noise and timing precision
Measuring count rates free from correlated noise in digital silicon photomultipliers
Abstract : The characterization of nuisance parameters in digital silicon photomultipliers (SiPMs) is important to their understanding and future development. Methods able to distinguish the types of events are necessary to obtain fair and legitimate measurements. In this work, the zero photon probability (ZPP) method and the time delay (TD) method are used to measure the dark noise of digital SiPMs free from the contribution of correlated noise such as afterpulsing and crosstalk. It highlights the unique features of digital SiPMs such as the holdoff delay, the digital output signal, and the embedded processing (e.g. the selection of the interval sampling width). The two methods correctly separate the correlated and uncorrelated events in digital SiPMs and therefore the determination of a true photon detection efficiency (PDE) is possible. The ZPP method is also implemented inside a digital SiPM using embedded digital signal processing
Analysis of detector performance in a gigahertz clock rate quantum key distribution system
We present a detailed analysis of a gigahertz clock rate environmentally robust phase-encoded quantum key distribution (QKD) system utilizing several different single-photon detectors, including the first implementation of an experimental resonant cavity thin-junction silicon single-photon avalanche diode. The system operates at a wavelength of 850 nm using standard telecommunications optical fibre. A general-purpose theoretical model for the performance of QKD systems is presented with reference to these experimental results before predictions are made about realistic detector developments in this system. We discuss, with reference to the theoretical model, how detector operating parameters can be further optimized to maximize key exchange rates
Laser Light Scattering, from an Advanced Technology Development Program to Experiments in a Reduced Gravity Environment
Recent advancements in laser light scattering hardware are described. These include intelligent single card correlators; active quench/active reset avalanche photodiodes; laser diodes; and fiber optics which were used by or developed for a NASA advanced technology development program. A space shuttle experiment which will employ aspects of these hardware developments is previewed
Controlling passively-quenched single photon detectors by bright light
Single photon detectors based on passively-quenched avalanche photodiodes can
be temporarily blinded by relatively bright light, of intensity less than a
nanowatt. I describe a bright-light regime suitable for attacking a quantum key
distribution system containing such detectors. In this regime, all single
photon detectors in the receiver Bob are uniformly blinded by continuous
illumination coming from the eavesdropper Eve. When Eve needs a certain
detector in Bob to produce a click, she modifies polarization (or other
parameter used to encode quantum states) of the light she sends to Bob such
that the target detector stops receiving light while the other detector(s)
continue to be illuminated. The target detector regains single photon
sensitivity and, when Eve modifies the polarization again, produces a single
click. Thus, Eve has full control of Bob and can do a successful
intercept-resend attack. To check the feasibility of the attack, 3 different
models of passively-quenched detectors have been tested. In the experiment, I
have simulated the intensity diagrams the detectors would receive in a real
quantum key distribution system under attack. Control parameters and side
effects are considered. It appears that the attack could be practically
possible.Comment: Experimental results from a third detector model added. Minor
corrections and edits made. 11 pages, 10 figure
A physically based model for evaluating the photon detection efficiency and the temporal response of SPAD detectors
Controlling an actively-quenched single photon detector with bright light
We control using bright light an actively-quenched avalanche single-photon
detector. Actively-quenched detectors are commonly used for quantum key
distribution (QKD) in the visible and near-infrared range. This study shows
that these detectors are controllable by the same attack used to hack
passively-quenched and gated detectors. This demonstrates the generality of our
attack and its possible applicability to eavsdropping the full secret key of
all QKD systems using avalanche photodiodes (APDs). Moreover, the commercial
detector model we tested (PerkinElmer SPCM-AQR) exhibits two new blinding
mechanisms in addition to the previously observed thermal blinding of the APD,
namely: malfunctioning of the bias voltage control circuit, and overload of the
DC/DC converter biasing the APD. These two new technical loopholes found just
in one detector model suggest that this problem must be solved in general, by
incorporating generally imperfect detectors into the security proof for QKD.Comment: Expanded discussions, updated references, added a picture of
decapsulated APD, reformatted to single-column style. Accepted to Opt.
Express. 11 pages, 6 figure
Characterizing a source of fission fragments for a gas jet
A model for the rate at which various primary fission products stop in the gas of the source chamber of a gas jet has been constructed. It describes the absorption of fission fragments in Al foils placed between the 235 U deposit and the gas chamber as well as the penetration of fragments through the gas. The model is based on reported ranges (mean values as a function of A and the dispersion in ranges) and measured activities of Kr and Xe.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43112/1/10967_2005_Article_BF02060552.pd
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
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