Search results for "Continuous"
showing 10 items of 899 documents
P-on-N and N-on-P silicon photomultipliers: an in-depth analysis in the continuous wave regime
2013
We report on the electrical and optical comparison, in the continuous wave regime, of two novel classes of silicon photomultipliers fabricated in planar technology on silicon P-type (N-on-P class) and N-type (P-on-N class) substrates respectively.
Continuous-wave cavity ring-down polarimetry
2020
We present a new cavity-based polarimetric scheme for highly sensitive and time-resolved measurements of birefringence and dichroism, linear and circular, that employs rapidly pulsed single-frequency continuous wave (CW) laser sources and extends current cavity-based spectropolarimetric techniques. We demonstrate how the use of a CW laser source allows for gains in spectral resolution, signal intensity, and data acquisition rate compared to traditional pulsed-based cavity ring-down polarimetry (CRDP). We discuss a particular CW-CRDP modality that is different from intensity-based cavity-enhanced polarimetric schemes as it relies on the determination of the polarization rotation frequency du…
Scaling and data collapse for the mean exit time of asset prices
2005
We study theoretical and empirical aspects of the mean exit time of financial time series. The theoretical modeling is done within the framework of continuous time random walk. We empirically verify that the mean exit time follows a quadratic scaling law and it has associated a pre-factor which is specific to the analyzed stock. We perform a series of statistical tests to determine which kind of correlation are responsible for this specificity. The main contribution is associated with the autocorrelation property of stock returns. We introduce and solve analytically both a two-state and a three-state Markov chain models. The analytical results obtained with the two-state Markov chain model …
A partially reflecting random walk on spheres algorithm for electrical impedance tomography
2015
In this work, we develop a probabilistic estimator for the voltage-to-current map arising in electrical impedance tomography. This novel so-called partially reflecting random walk on spheres estimator enables Monte Carlo methods to compute the voltage-to-current map in an embarrassingly parallel manner, which is an important issue with regard to the corresponding inverse problem. Our method uses the well-known random walk on spheres algorithm inside subdomains where the diffusion coefficient is constant and employs replacement techniques motivated by finite difference discretization to deal with both mixed boundary conditions and interface transmission conditions. We analyze the global bias…
Use of a Continuous Wave Laser and Pockels Cell for Sensitive High-Resolution Collinear Resonance Ionization Spectroscopy
2015
New technical developments have led to a 2 orders of magnitude improvement of the resolution of the collinear resonance ionization spectroscopy (CRIS) experiment at ISOLDE, CERN, without sacrificing the high efficiency of the CRIS technique. Experimental linewidths of 20(1) MHz were obtained on radioactive beams of francium, allowing us for the first time to determine the electric quadrupole moment of the short lived [t1/2=22.0(5) ms]219Fr Qs=−1.21(2) eb, which would not have been possible without the advantages offered by the new method. This method relies on a continuous-wave laser and an external Pockels cell to produce narrow-band light pulses, required to reach the high resolution in t…
A superconducting CW-LINAC for heavy ion acceleration at GSI
2017
The European physical journal / Web of Conferences 138, 01026 (2017). doi:10.1051/epjconf/201713801026
Assessment of the CTOCD-DZ methodin a hierarchy of coupled cluster methods
2010
Gauge origin independent calculations of nuclear magnetic shielding tensors are carried out inside the formalism of the continuous transformation of the origin of the current density leading to formal annihilation of its diamagnetic contribution (CTOCD-DZ). We employ the unrelaxed linear response approach with a hierarchy of different coupled cluster methods in order to assess the importance of the level of approximation in the coupled cluster expansion. The basis set dependence of the computed nuclear magnetic shielding constants is also analyzed in the series of correlation consistent basis sets, with the aim of designing optimized basis sets of relatively small size.
Free-motion beam propagation factor measurement by means of a liquid crystal SLM
2011
We propose a compact and robust method to measure beam propagation factor (M2) of continuous wave (cw) laser beams. In contrast to the conventional scanning procedure described in the ISO/DIS 11146 standard, our proposal takes advantage of the features of programmable liquid crystal spatial light modulators (SLMs) where a lens is codified. Then, by using a CCD at a fixed position, the beam width according to the second order moment of the irradiance is determined for each focal length of the codified lenses. After adjusting the measured data to the theoretical focusing behavior of a real laser beam, the beam propagation factor is obtained. The proposed method was successfully validated in t…
Temperature dependence of the effective mobility edge and recombination dynamics of free and localized excitons in InGaP/GaAs quantum wells
2003
3 páginas, 1 figura.-- Comunicación presentada al Proceedings of the International Conference on Superlattices, Nano-structures and Nano-devices ICSNN 2002 o-structures and Nano-devices ICSNN 2002.
Zeno-like phenomena in STIRAP processes
2011
The presence of a continuous measurement quantum Zeno effect in a stimulated Raman adiabatic passage is studied, exploring in detail a sort of self-competition of the damping, which drives the system toward a loss of population and, at the same time, realizes the conditions for optimizing the adiabatic passage.