8,027 research outputs found
Design of a spiral-shaped Mach Zehnder interferometric sensor for refractive index sensing of watery solutions
The design of a spiral-shaped Mach-Zehnder Interferometric sensor (sMZI sensor) for refractive index sensing of watery solutions is presented. The goal of the running project is to realise a multi-sensing array by placing multiple sMZIs in series to form a sensing branch, and to place several sensing branches in parallel. In such an arrangment it is possible to use a single light source for several sensors. Each sensor will contain an electro-optical modulator, which makes it possible to separately interrogate and accurately read-out each sensor in the same sensing branch
Statistical uncertainties and systematic errors in weak lensing mass estimates of galaxy clusters
Upcoming and ongoing large area weak lensing surveys will also discover large
samples of galaxy clusters. Accurate and precise masses of galaxy clusters are
of major importance for cosmology, for example, in establishing well calibrated
observational halo mass functions for comparison with cosmological predictions.
We investigate the level of statistical uncertainties and sources of systematic
errors expected for weak lensing mass estimates. Future surveys that will cover
large areas on the sky, such as Euclid or LSST and to lesser extent DES, will
provide the largest weak lensing cluster samples with the lowest level of
statistical noise regarding ensembles of galaxy clusters. However, the expected
low level of statistical uncertainties requires us to scrutinize various
sources of systematic errors. In particular, we investigate the bias due to
cluster member galaxies which are erroneously treated as background source
galaxies due to wrongly assigned photometric redshifts. We find that this
effect is significant when referring to stacks of galaxy clusters. Finally, we
study the bias due to miscentring, i.e., the displacement between any
observationally defined cluster centre and the true minimum of its
gravitational potential. The impact of this bias might be significant with
respect to the statistical uncertainties. However, complementary future
missions such as eROSITA will allow us to define stringent priors on
miscentring parameters which will mitigate this bias significantly.Comment: 14 pages, 7 figures; accepted for publication in MNRA
Modulation-frequency encoded multi-wavelength fluorescence analysis
We introduce a principle of parallel optical processing: modulation-frequency-encoded multi-wavelength laser excitation, fluorescence detection with a single detector, and Fourier analysis decoding. As an example, we demonstrate simultaneous detection of DNA fragments from different origins
Multi-color fluorescent DNA analysis in an optofluidic chip
Modulation-frequency-encoded fluorescence excitation enables the identification of end-labeled DNA samples of different genetic origin during their electrophoretic separation, opening perspectives for intrinsic size calibration, malign / healthy sample comparison, and exploitation of multiplex ligation-dependent probe amplification
Weak lensing constraints on splashback around massive clusters
The splashback radius separates the physical regimes of
collapsed and infalling material around massive dark matter haloes. In
cosmological simulations, this location is associated with a steepening of the
spherically averaged density profile . In this work, we measure the
splashback feature in the stacked weak gravitational lensing signal of
massive clusters from the Cluster Canadian Comparison Project with careful
control of residual systematics effects. We find that the shear introduced by
the presence of additional structure along the line of sight significantly
affects the noise at large clustercentric distances. Although we do not detect
a significant steepening, the use of a simple parametric model enables us to
measure both comoving Mpc and the value of the
logarithmic slope at this point,
.Comment: 9 pages, 5 figures. Accepted for publication in MNRA
A spiral-shaped mach-zehnder interferometric sensor for monitoring thickness changes in bioreceptor layers
Design issues of a spiral-shaped Mach-Zehnder interferometer are discussed
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