Search results for "pulse"
showing 10 items of 1508 documents
Demonstration of an efficient pumping scheme for a 7.36-nm Ni-like samarium soft x-ray laser
2010
The demonstration of a 7.36 nm Ni-like Sm soft x-ray laser pumped by 36 J of a Nd:glass chirped pulse amplification laser is presented. Double-pulse single-beam non-normal incidence pumping was applied for the efficient soft x-ray laser generation. Here the applied technique included a new single optic focusing geometry for large beam diameters, a single-pass grating compressor traveling-wave tuning capability and an optimized high energy laser double-pulse. This scheme has the potential for even shorter wavelength soft x-ray laser pumping.
<title>New PW stretcher-compressor design for PHELIX laser</title>
2005
With PHELIX (Petawatt High Energy Laser for heavy Ion EXperiments) a high energy/ultra-high intensity laser system is currently under construction at the GSI (Gesellschaft fur SchwerIonenforschung, Germany). In combination with the high current high energy ion accelerator facility this will provide worldwide unique experimental opportunities in the field of dense plasma physics and inertial fusion research. In the long pulse mode the laser system will provide laser pulses of up to 5 kJ in 1-10 ns pulses. In the high intensity mode pulse powers in excess of 1 PW will be achieved. For this the well known technique of chirped pulse amplification (CPA) will be implemented. A new CPA stretcher-c…
Ytterbium-doped fibers for high-power fiber lasers
2021
Ytterbium (Yb) doped optical fibers are widely used in high-power applications and ultrafast lasing since they show adequate power-handling capability and provide desirable beam quality. Yb-doped fibers with large core area can support high power but often act as a multimode fiber and compromise the output beam quality. Hence, it is important to attain a proper balance between the power-handling capability and the beam quality. Yb-doped fibers as a gain medium in pulsed fiber laser systems are prone to nonlinear optical effects due to the presence of high peak power in the ultrashort pulses. Nonlinearity such as self phase modulation (SPM) affects the width and the shape of the pulse, both …
Early folding events during light harvesting complex II assembly in vitro monitored by pulsed electron paramagnetic resonance
2016
Efficient energy transfer in the major light harvesting complex II (LHCII) of green plants is facilitated by the precise alignment of pigments due to the protein matrix they are bound to. Much is known about the import of the LHCII apoprotein into the chloroplast via the TOC/TIC system and its targeting to the thylakoid membrane but information is sparse about when and where the pigments are bound and how this is coordinated with protein folding. In vitro, the LHCII apoprotein spontaneously folds and binds its pigments if the detergent-solubilized protein is combined with a mixture of chlorophylls a and b and carotenoids. In the present work, we employed this approach to study apoprotein fo…
How the Protein Environment Can Tune the Energy, the Coupling, and the Ultrafast Dynamics of Interacting Chlorophylls: The Example of the Water-Solub…
2020
The interplay between active molecules and the protein environment in light-harvesting complexes tunes the photophysics and the dynamical properties of pigment–protein complexes in a subtle way, which is not fully understood. Here we characterized the photophysics and the ultrafast dynamics of four variants of the water-soluble chlorophyll protein (WSCP) as an ideal model system to study the behavior of strongly interacting chlorophylls. We found that when coordinated by the WSCP protein, the presence of the formyl group in chlorophyll b replacing the methyl group in chlorophyll a strongly affects the exciton energy and the dynamics of the system, opening up the possibility of tuning the ph…
Instantaneous frequency measurement of dissipative soliton resonant light pulses
2016
Fil: Cuadrado-Laborde, Christian. Universidad de Valencia. Departamento de Física Aplicada y Electromagnetismo. Instituto Universitario de Ciencia de los Materiales; España Fil: Cuadrado-Laborde, Christian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Física Rosario; Argentina Fil: Cuadrado-Laborde, Christian. Pontificia Universidad Católica Argentina. Facultad de Química e Ingeniería del Rosario; Argentina Fil: Armas Rivera, I. Benemérita Universidad Autónoma de Puebla. Facultad de Ciencias Físico Matemáticas; Mexico Fil: Carrascosa, A. Universidad de Valencia. Departamento de Física Aplicada y Electromagnetismo. Instituto Universitario de Ciencia de los Materia…
Long-period grating assisted fractional differentiation of highly chirped light pulses
2016
We experimentally demonstrate the possibility to perform a fractional differentiation of arbitrary order on a given light pulse by propagation through a single long-period grating. A simple analytical expression is obtained also, relating the fractional order of differentiation with the parameters of the long-period grating. A secant hyperbolic like pulse of 23 ps time width with a chirp parameter of -30 was successfully fractionally differentiated to the 0.5th order. The proposal was corroborated experimentally and numerically. The device may find applications in real time phase recovery. Fil: Poveda Wong, L.. Universidad de Valencia; España Fil: Carrascosa, A.. Universidad de Valencia; Es…
Innovative “Green” and Novel Strategies for the Extraction of Bioactive Added Value Compounds from Citrus Wastes—A Review
2017
Citrus is a major processed crop that results in large quantities of wastes and by-products rich in various bioactive compounds such as pectins, water soluble and insoluble antioxidants and essential oils. While some of those wastes are currently valorised by various technologies (yet most are discarded or used for feed), effective, non-toxic and profitable extraction strategies could further significantly promote the valorisation and provide both increased profits and high quality bioactives. The present review will describe and summarize the latest works concerning novel and greener methods for valorisation of citrus by-products. The outcomes and effectiveness of those technologies such a…
Optical systems for non-invasive cardiovascular biosensing
2005
Three portable prototype devices for cardiovascular biosensing based on reflection-type photoplethysmography (PPG) principle have been designed and clinically tested. The single-channel PPG finger sensor provides real-time measurements with fast calculation of the mean single-period PPG signal shape ("cardiovascular fingerprint", potentially useful for recognition). The dual-channel PPG system gives additional possibility to monitor on-line the arterial pulse wave transit time and its responses to physical exercises. The four-channel PPG system proved to be applicable for fast detection of cardiovascular pathologies, e.g. arterial occlusions in extremities. Design principles and software al…
Active spike transmission in the neuron model with a winding threshold manifold
2012
International audience; We analyze spiking responses of excitable neuron model with a winding threshold manifold on a pulse stimulation. The model is stimulated with external pulse stimuli and can generate nonlinear integrate-and-fire and resonant responses typical for excitable neuronal cells (all-or-none). In addition we show that for certain parameter range there is a possibility to trigger a spiking sequence with a finite number of spikes (a spiking message) in the response on a short stimulus pulse. So active transformation of N incoming pulses to M (with M>N) outgoing spikes is possible. At the level of single neuron computations such property can provide an active "spike source" comp…