Publication

Slow, superluminal and negative group velocity in optical fibres using stimulated Brillouin scattering

Publications associées (28)

Space-time wave packets with reduced divergence and tunable group velocity generated in free space after multi-mode fiber propagation

Tobias Kippenberg, Hao Song, Maxim Karpov, Xinzhou Su

Previously, space-time wave packets (STWPs) have been gen-erated in free space with reduced diffraction and a tunable group velocity by combining multiple frequency comb lines each carrying a single Bessel mode with a unique wave num-ber. It might be poten ...

Optica Publishing Group2023

Impact of the turbulence wavenumber spectrum and probing beam geometry on Doppler reflectometry perpendicular velocity measurements

Frank Nüesch, Anita Frank

The perpendicular propagation velocity of turbulent density fluctuations is an important parameter in fusion plasmas, since sheared plasma flows are crucial for reducing turbulence, and thus an essential input parameter for turbulent transport simulations. ...

IOP Publishing Ltd2023

Spin wave dispersion of ultra-low damping hematite (α-Fe2O3) at GHz frequencies

Dirk Grundler, Ferdinand Rémy Hynek Posva, Mohammad Hamdi

Raw data associated to the manuscript ‘’Spin wave dispersion of ultra-low damping hematite (α-Fe2O3) at GHz frequencies‘’, Physical Review Materials 7, 054407(2023); doi: 10.1103/PhysRevMaterials.7.054407 Information about file fo ...

Zenodo2023

Spin wave dispersion of ultra-low damping hematite ( α−Fe2O3 ) at GHz frequencies

Dirk Grundler, Ferdinand Rémy Hynek Posva, Mohammad Hamdi

Low magnetic damping and high group velocity of spin waves (SWs) or magnons are two crucial parameters for functional magnonic devices. Magnonics research on signal processing and wave-based computation at GHz frequencies focused on the artificial ferrimag ...

2023

Low-Loss Anisotropic Image Polaritons in van der Waals Crystal alpha-MoO3

Sergejs Boroviks

Orthorhombic molybdenum trioxide (alpha-MoO3), a newly discovered polaritonic van der Waals crystal, is attracting significant attention due to its strongly anisotropic mid-infrared phonon-polaritons. At the same time, coupling of polariton with its mirror ...

WILEY-V C H VERLAG GMBH2022

Estimating the non-dimensional energy of vortex rings by modelling their roll-up

Karen Ann J Mulleners, Guillaume de Guyon-Crozier

The non-dimensional energy of starting vortex rings typically converges to values around 0.33 when they are created by a piston-cylinder or a bluff body translating at a constant speed. To explore the limits of the universality of this value and to analyse ...

Cambridge University Press2022

The 2021 Magnonics Roadmap

Dirk Grundler, Joyeeta Sinha, Heena Yang, Thomas Yu

Magnonics is a budding research field in nanomagnetism and nanoscience that addresses the use of spin waves (magnons) to transmit, store, and process information. The rapid advancements of this field during last one decade in terms of upsurge in research p ...

2021

An Extension of the Guided Wave M‐Component Model Taking Into Account the Presence of a Tall Strike Object

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Mi Zhou, Qi Li

We present in this paper an extension of the guided-wave M-component model of Rakov et al. considering the presence of a vertically elevated strike object. The tall object is represented as a lossless, uniform transmission line. Expressions for the current ...

2021

Brillouin scattering in gas-filled hollow-core fibres

Flavien Gyger

Edward E. Hagenlocker and William G. Rado demonstrated Brillouin interaction in gas for the first time in 1965, right after the very first demonstrations of stimulated Brillouin scattering in solid materials. In their experiment, they used a megawatt pulse ...

EPFL2020

Attenuation of Lamb Modes and SH Waves near cut-off Frequencies

Victor Plessky, Soumya Yandrapalli

Near cut-off frequencies, the shear horizontal (SH) and Lamb modes in a platelet are created by a bulk acoustic wave bouncing up and down between the platelet sides in an almost vertical direction. The small inclination angle corresponds to slow drift of e ...

IEEE2020

One-minute average cruise track and ship velocity of the Antarctic Circumnavigation Expedition (ACE) undertaken during the austral summer of 2016/2017

Jenny Thomas, Julia Schmale, Sebastian Johannes Heinz-Josef Landwehr

Dataset abstract The ship's cruise track, velocity, course over ground and heading at one-minute resolution for all five legs of the Antarctic Circumnavigation Expedition (ACE) are derived from a combination of: - the latitude/longitud ...

2020

Chiral Spin-Wave Velocities Induced by All-Garnet Interfacial Dzyaloshinskii-Moriya Interaction in Ultrathin Yttrium Iron Garnet Films

Haiming Yu, Song Liu, Peng Gao, Dirk Grundler, Ping Che, Yuehui Li, Sa Tu, Jilei Chen, Jianyu Zhang, Tao Liu

Spin waves can probe the Dzyaloshinskii-Moriya interaction (DMI), which gives rise to topological spin textures, such as skyrmions. However, the DMI has not yet been reported in yttrium iron garnet (YIG) with arguably the lowest damping for spin waves. In ...

2020

Particle transport at arbitrary timescales with Poisson-distributed collisions

Ambrogio Fasoli, Ivo Furno, Paolo Ricci, Marcelo Baquero Ruiz, Fabian Manke

We develop a model to investigate the time evolution of the mean location and variance of a random walker subject to Poisson-distributed collisions at constant rate. The collisions are instantaneous velocity changes where a new value of velocity is generat ...

2019

Ultrabroadband 3D invisibility with fast-light cloaks

Hatice Altug, Dordaneh Etezadi, Kosmas Tsakmakidis, Foziyeh Sohrabi, Ershad Mohammadi

An invisibility cloak should completely hide an object from an observer, ideally across the visible spectrum and for all angles of incidence and polarizations of light, in three dimensions. However, until now, all such devices have been limited to either s ...

Nature Research2019

Multirotor UAV-based platform for the measurement of atmospheric turbulence: validation and signature detection of tip vortices of wind turbine blades

Fernando Porté Agel, Lionel Wilhelm, Fernando Carbajo Fuertes

The present study describes the development of a technique for the measurement of atmospheric turbulence and temperature at a point in space based on the integration of a fast-response multi-hole pressure probe and a thermocouple with an inertial measureme ...

2019

Two-degrees-of-freedom (PID)-D-2 controller for precise nanopositioning in the presence of hardware-induced constant time delay

Andres San Millan Rodriguez

The fast and accurate tracking of periodic and arbitrary reference trajectories is the principal goal in many nanopositioning applications. Flexure-based piezoelectric stack driven nanopositioners are widely employed in applications where accurate mechanic ...

ELSEVIER SCIENCE INC2019

Innovative measurement techniques for atmospheric turbulence and wind energy

Fernando Carbajo Fuertes

The measurement of different atmospheric flow quantities is of utmost importance for a correct understanding of most atmospheric phenomena. Researchers and industry in the fields of meteorology and wind engineering demand extensive and accurate measurement ...

EPFL2018

Effect of spilling from adjacent orifices on the velocity field and pressures in front of needle stop-logs

Giovanni De Cesare, Azin Amini, Cédric Bron, Ivan Stojnic

In this study, the effect of spilling from neighboring sluice gates on stop-logs was experimentally investigated on a 1:65 physical scale model comprised of a double arch dam, a reservoir area, six spillway orifices and two stop-logs. Two types of measurem ...

2018

Distributed analyses using distinct classes of Brillouin scatterings in optical fibres

Desmond Chow Ming Chia

Brillouin scattering is an interaction between light and sound in a material. This inelastic light scattering had been observed in the first optical fibres that were used in cross-continent communication. Via Brillouin scattering, the guided light wave in ...

EPFL2018

Generalized resolution matrix for neutron spin-echo three-axis spectrometers

Thomas Keller, Felix Groitl

This article describes the energy resolution of spin-echo three-axis spectrometers (SE-TASs) by a compact matrix formalism. SE-TASs allow one to measure the line widths of elementary excitations in crystals, such as phonons and magnons, with an energy reso ...

INT UNION CRYSTALLOGRAPHY2018