4,711 research outputs found
Realization of an Economical Polymer Optical Fiber Demultiplexer
Polymer Optical Fiber (POF) can be and are being used in various fields of
applications. Two of the main fields are the automotive and the home
entertainment sector. The POF can be applied in several different optical
communication systems as automotive multi-media busses or in-house Ethernet
systems.
The requirements of bandwidth are increasing very fast in these sectors and
therefore solutions that satisfy these demands are of high actuality. One
solution is to use the wavelength division multiplexing (WDM) technique. Here,
several different wavelengths can carry information over one POF fiber. All
wavelengths that are transmitted over the fiber, must be separated at the
receiver to regain and redirect the information channels. These separators are
so-called Demultiplexers.
There are several systems available on the market, which are all afflicted
with certain disadvantages. But all these solutions have one main disadvantage,
they are all too expensive for most of the applications mentioned above. So the
goal of this study is to develop an economical Demultiplexer for WDM
transmission over POF.
The main idea is to separate the chromatic light in its monochromatic
components with the help of a prism with low reciprocal dispersive power. The
prism and the other assemblies, which are needed to adjust the optical path,
should be manufactured in injection molding technique. This manufacturing
technique is a very simple and economical way to produce a mass production
applicable Demultiplexer for POF.Comment: 2006 International Students and Young Scientists Workshop "Photonics
and Microsystems
PSAMMOCHARIDAE VON DEN KRAKATAU-INSELN
abstract not availabl
Static observables of relativistic three-fermion systems with instantaneous interactions
We show that static properties like the charge radius and the magnetic moment
of relativistic three-fermion bound states with instantaneous interactions can
be formulated as expectation values with respect to intrinsically defined
wavefunctions. The resulting operators can be given a natural physical
interpretation in accordance with relativistic covariance. We also indicate how
the formalism may be generalized to arbitrary moments. The method is applied to
the computation of static baryon properties with numerical results for the
nucleon charge radii and the baryon octet magnetic moments. In addition we make
predictions for the magnetic moments of some selected nucleon resonances and
discuss the decomposition of the nucleon magnetic moments in contributions of
spin and angular momentum, as well as the evolution of these contributions with
decreasing quark mass.Comment: 13 pages, including 2 figures and 3 tables, submitted to Eur.Phys.J.
Anomalous suppression of the shot noise in a nanoelectromechanical system
In this paper we report a relaxation-induced suppression of the noise for a
single level quantum dot coupled to an oscillator with incoherent dynamics in
the sequential tunneling regime. It is shown that relaxation induces
qualitative changes in the transport properties of the dot, depending on the
strength of the electron-phonon coupling and on the applied voltage. In
particular, critical thresholds in voltage and relaxation are found such that a
suppression below 1/2 of the Fano factor is possible. Additionally, the current
is either enhanced or suppressed by increasing relaxation, depending on bias
being greater or smaller than the above threshold. These results exist for any
strength of the electron-phonon coupling and are confirmed by a four states toy
model.Comment: 7 pages, 7 eps figures, submitted to PRB; minor changes in the
introductio
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