2,516 research outputs found
Characterisation of the Etching Quality in Micro-Electro-Mechanical Systems by Thermal Transient Methodology
Our paper presents a non-destructive thermal transient measurement method
that is able to reveal differences even in the micron size range of MEMS
structures. Devices of the same design can have differences in their
sacrificial layers as consequence of the differences in their manufacturing
processes e.g. different etching times. We have made simulations examining how
the etching quality reflects in the thermal behaviour of devices. These
simulations predicted change in the thermal behaviour of MEMS structures having
differences in their sacrificial layers. The theory was tested with
measurements of similar MEMS devices prepared with different etching times. In
the measurements we used the T3Ster thermal transient tester equipment. The
results show that deviations in the devices, as consequence of the different
etching times, result in different temperature elevations and manifest also as
shift in time in the relevant temperature transient curves.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Measurement of the Cosmic Optical Background using the Long Range Reconnaissance Imager on New Horizons
The cosmic optical background is an important observable that constrains
energy production in stars and more exotic physical processes in the universe,
and provides a crucial cosmological benchmark against which to judge theories
of structure formation. Measurement of the absolute brightness of this
background is complicated by local foregrounds like the Earth's atmosphere and
sunlight reflected from local interplanetary dust, and large discrepancies in
the inferred brightness of the optical background have resulted. Observations
from probes far from the Earth are not affected by these bright foregrounds.
Here we analyze data from the Long Range Reconnaissance Imager (LORRI)
instrument on NASA's New Horizons mission acquired during cruise phase outside
the orbit of Jupiter, and find a statistical upper limit on the optical
background's brightness similar to the integrated light from galaxies. We
conclude that a carefully performed survey with LORRI could yield uncertainties
comparable to those from galaxy counting measurements.Comment: 35 pages, 11 figures, published in Nature Communication
A Novel Protocol-Authentication Algorithm Ruling Out a Man-in-the-Middle Attack in Quantum Cryptography
In this work we review the security vulnerability of Quantum Cryptography
with respect to "man-in-the-middle attacks" and the standard authentication
methods applied to counteract these attacks. We further propose a modified
authentication algorithm which features higher efficiency with respect to
consumption of mutual secret bits.Comment: 4 pages, submitted to the International Journal of Quantum
Information, Proceedings of the meeting "Foundations of Quantum Information",
Camerino, April 200
Modeling of 3D fluid-structure-interaction during in-situ hybridization of double-curved fiber-metal-laminates
FM 047-02: a collisional pair of galaxies with a ring
Aims. We investigate the nature of the galaxy pair FM 047-02, which has been
proposed as an archetype of the Solitaire types of peculiar (collisional) ring
galaxies. Methods. The study is based on long-slit spectrophotometric data in
the range of 3500-9500 angstrons obtained with the Gemini Multi-ObjectComment: 07 pages, 06 figures, 02 tables. arXiv admin note: text overlap with
arXiv:1206.071
Discrete structure of ultrathin dielectric films and their surface optical properties
The boundary problem of linear classical optics about the interaction of
electromagnetic radiation with a thin dielectric film has been solved under
explicit consideration of its discrete structure. The main attention has been
paid to the investigation of the near-zone optical response of dielectrics. The
laws of reflection and refraction for discrete structures in the case of a
regular atomic distribution are studied and the structure of evanescent
harmonics induced by an external plane wave near the surface is investigated in
details. It is shown by means of analytical and numerical calculations that due
to the existence of the evanescent harmonics the laws of reflection and
refraction at the distances from the surface less than two interatomic
distances are principally different from the Fresnel laws. From the practical
point of view the results of this work might be useful for the near-field
optical microscopy of ultrahigh resolution.Comment: 25 pages, 16 figures, LaTeX2.09, to be published in Phys.Rev.
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
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