Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Concept

Orbital angular momentum of light

Publications associées (31)

Modeling of second-order nonlinear metasurfaces

Olivier Martin, Karim Achouri, Andrei Kiselev

We present a frequency-domain modeling technique for second-order nonlinear metasurfaces. The technique is derived from the generalized sheet transition conditions (GSTCs), which have been so far mostly used for modeling linear metasurfaces. In this work, ...

IOP Publishing Ltd2022

Angular systematics-free cosmological analysis of galaxy clustering in configuration space

Cheng Zhao, Anand Stéphane Raichoor

Galaxy redshift surveys are subject to incompleteness and inhomogeneous sampling due to the various constraints inherent to spectroscopic observations. This can introduce systematic errors on the summary statistics of interest, which need to be mitigated i ...

OXFORD UNIV PRESS2022

Spectral self-imaging of optical orbital angular momentum modes

Camille Sophie Brès, Jianqi Hu

The Talbot self-imaging effect is mostly present in the forms of space or time, or in the frequency domain by the Fourier duality. Here, we disclose a new spectral Talbot effect arising in optical orbital angular momentum (OAM) modes. The effect occurs in ...

AIP Publishing2021

Tomographic reconstruction of the runaway distribution function in TCV using multispectral synchrotron images

Basil Duval, Joan Decker, Umar Sheikh, Artur Perek

Synchrotron radiation observed in a quiescent Tokamak a Configuration Variable (TCV) runaway discharge is studied using filtered camera images targeting three distinct wavelength intervals. Through the tomographic simultaneous algebraic reconstruction tech ...

IOP Publishing Ltd2021

Metasurfaces for label-free biosensing mid-infrared optics and active photonic devices

Aleksandrs Leitis

Novel two-dimensional metamaterials, known as metasurfaces, have emerged as a breakthrough platform for controlling electromagnetic wave properties at the nanoscale. These metasurfaces consist of subwavelength nanoantennas or so-called meta-atoms, which ca ...

EPFL2021

Versatile shaping of optical frequency combs and applications

Jianqi Hu

Optical frequency combs are a series of phase-locked and equidistant laser lines in the spectral domain. In the time domain, they correspond to periodic pulse trains by the Fourier relation. The ability to shape optical combs and pulse trains is pivotal to ...

EPFL2021

Quasi-Global Momentum: Accelerating Decentralized Deep Learning on Heterogeneous Data

Martin Jaggi, Sebastian Urban Stich, Tao Lin, Sai Praneeth Reddy Karimireddy

Decentralized training of deep learning models is a key element for enabling data privacy and on-device learning over networks. In realistic learning scenarios, the presence of heterogeneity across different clients' local datasets poses an optimization ch ...

JMLR-JOURNAL MACHINE LEARNING RESEARCH2021

Parallel Analog Computing Based on a 2×2 Multiple-Input Multiple-Output Metasurface Processor With Asymmetric Response

Romain Christophe Rémy Fleury, Ali Momeni

We present a polarization-insensitive metasurface processor to perform spatial asymmetric filtering of an incident beam, thereby allowing for real-time parallel analog processing. To enable massive parallel processing, we introduce a multiple-input multipl ...

American Physical Society (APS)2021

Development of a novel two-phase flow solver for nuclear reactor analysis: algorithms, verification and implementation in OpenFOAM

Andreas Pautz, Carlo Fiorina, Stefan Radman

A porous medium-based representation of nuclear reactors and complex engineering systems more in general can significantly reduce simulation and modelling costs, while preserving a reasonable degree of accuracy via regime map-based correlations for modelli ...

2021

High speed, complex wavefront shaping using the digital micro-mirror device

Demetri Psaltis

Digital micro-mirror devices (DMDs) have been deployed in many optical applications. As compared to spatial light modulators (SLMs), they are characterized by their much faster refresh rates (full-frame refresh rates up to 32 kHz for binary patterns) compa ...

Nature Portfolio2021

Second harmonic generation in glass-based metasurfaces using tailored surface lattice resonances

Olivier Martin, Fabien Sorin, Jérémy Butet, Wei Yan, Kuang-Yu Yang, Dang Tùng Nguyen, Andreas Leber, Chaoqun Dong

Dielectric metasurfaces have shown prominent applications in nonlinear optics due to strong field enhancement and low dissipation losses at the nanoscale. Chalcogenide glasses are one of the promising materials for the observation of nonlinear effects than ...

2021