Publications associées à Optimal cell topology constraint for monolayer dual-polarized beamscanning reflectarrays

Spun fibres: a quasi circularly birefringent medium

Luc Thévenaz, Ana Gabriela Correa Mena, Xu Cheng

A simplified model describing the polarisation characteristics of spun fibres is proposed, aiming at determining how close to a circularly birefringent medium such a fibre is. This is of crucial importance regarding the interest of such a medium for magnet ...

SPIE2023

Exploring Novel Modalities for Optical Diffraction Tomography

Amirhossein Saba Shirvan

In the past decade, optical diffraction tomography has gained a lot of attention for its ability to create label-free three-dimensional (3D) images of the refractive index distribution of biological samples using scattered fields measured through holograph ...

EPFL2023

Dielectric Tetramer Nanoresonators Supporting Strong Superchiral Fields for Vibrational Circular Dichroism Spectroscopy

Hatice Altug, Yasaman Jahani, Bang Hyun Lee, Ming-Lun Tseng, Rui Lu, Longfang Ye, Felix Ulrich Richter

Chirality (C) is a fundamental property of objects, in terms of symmetry. It is extremely important to sense and distinguish chiral molecules in the fields of biochemistry, science, and medicine. Vibrational circular dichroism (VCD) spectroscopy, obtained ...

Amer Chemical Soc2023

Optical metasurfaces: synthesis, nanofabrication, and colorful applications

Hsiang-Chu Wang

In this thesis, we mainly utilize silver to construct the meta-atoms. Although suffering from easily oxidized, its excellent lossless property throughout the visible range makes it suitable for study. When preserved properly, silver-made metasurfaces can s ...

EPFL2022

Plasmonic nanobar-on-mirror antenna with giant local chirality: a new platform for ultrafast chiral single-photon emission

Wen Chen, Kai Wang

Providing an additional degree of freedom for binary information encoding and nonreciprocal information transmission, chiral single photons have become a new research frontier in quantum optics. Without using complex external conditions (e.g., magnetic fie ...

ROYAL SOC CHEMISTRY2022

Thermally reconfigurable metalens

Giulia Tagliabue, Nathanaël Restori, Anna Archetti, Fateme Kiani Shahvandi, Theodoros Tsoulos, Ren-Jie Lin

Reconfigurable metalenses are compact optical components composed by arrays of meta-atoms that offer unique opportunities for advanced optical systems, from microscopy to augmented reality platforms. Although poorly explored in the context of reconfigurabl ...

WALTER DE GRUYTER GMBH2022

Nonlinear Inverse Problems in Quantitative Phase Imaging

Thanh-An Michel Pham

The topic of this thesis is the development of new algorithmic reconstruction methods for quantitative phase imaging (QPI). In the past decade, advanced QPI has emerged as a valuable tool to study label-free biological samples and uncover their 3D structur ...

EPFL2022

The new X-ray/visible microscopy MAXWELL technique for fast three-dimensional nanoimaging with isotropic resolution

Giorgio Margaritondo, Lin Yang

Microscopy by Achromatic X-rays With Emission of Laminar Light (MAXWELL) is a new X-ray/visible technique with attractive characteristics including isotropic resolution in all directions, large-volume imaging and high throughput. An ultrathin, laminar X-ra ...

Nature Portfolio2022

General invariance and equilibrium conditions for lattice dynamics in 1D, 2D, and 3D materials

Nicola Marzari, Samuel Poncé, Changpeng Lin

The long-wavelength behavior of vibrational modes plays a central role in carrier transport, phonon-assisted optical properties, superconductivity, and thermomechanical and thermoelectric properties of materials. Here, we present general invariance and equ ...

NATURE PORTFOLIO2022

Reciprocal Metasurfaces for On-axis Reflective Optical Computing

Karim Achouri, Romain Christophe Rémy Fleury, Ali Momeni

Analog computing has emerged as a promising candidate for real-time and parallel continuous data processing. This paper presents a reciprocal way for realizing asymmetric optical transfer functions (OTFs) in the reflection side of the on-axis processing ch ...

2021

Polarization-sensitive optics diffraction tomography

Demetri Psaltis, Ahmed Ayoub, Joowon Lim, Elizabeth Elena Antoine, Amirhossein Saba Shirvan

Polarization of light has been widely used as a contrast mechanism in two-dimensional (2D) microscopy and also in some three-dimensional (3D) imaging modalities. In this paper, we report the 3D tomographic reconstruction of the refractive index (RI) tensor ...

2021

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

Development of novel experimental and computational methods for three-dimensional coherent and super-resolution microscopy

Adrien Charles-François Raymond Descloux

Optical microscopy is one widely used tool to study cell functions and the interaction of molecules at a sub-cellular level. Optical microscopy techniques can be broadly divided into two categories: partially coherent and incoherent. Coherent microscopy te ...

EPFL2020

Tokamak plasma edge studies by microwave short-pulse reflectometry and backscattering

Pedro Andres Molina Cabrera

Moving towards an increased understanding of the dynamic processes in the edge of tokamak plasmas requires continuous innovation in diagnostic capabilities, pushing the envelope in both spatial and temporal dimenstions. Plasma density and rotation, and the ...

EPFL2019

Controlling Polarization in Personalization: An Algorithmic Framework

Nisheeth Vishnoi, Farnood Salehi, Laura Elisa Celis, Sayash Kapoor

Personalization is pervasive in the online space as it leads to higher efficiency for the user and higher revenue for the platform by individualizing the most relevant content for each user. However, recent studies suggest that such personalization can lea ...

ASSOC COMPUTING MACHINERY2019

Terahertz Quarter Wave-Plate Metasurface Polarizer Based on Arrays of Graphene Ribbons

Babak Rahmani

We propose a novel graphene-dielectric-based meta-surface for manipulating the polarization of the incident light in the terahertz regime. The proposed structure comprised two orthogonally oriented periodic array of graphene ribbons (PAGRs) which are separ ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2019

Accessible Superchiral Near-Fields Driven by Tailored Electric and Magnetic Resonances in All-Dielectric Nanostructures

Hatice Altug, Andreas Tittl, Yasaman Jahani, Kosmas Tsakmakidis, Ershad Mohammadi

Detection and differentiation of enantiomers in small quantities are crucially important in many scientific fields, including biology, chemistry, and pharmacy. Chiral molecules manifest their handedness in their interaction with the chiral state of light ( ...

AMER CHEMICAL SOC2019

Ultrafast broadband circular dichroism in the deep ultraviolet

Majed Chergui, Jérôme Lacour, Thomas Charles Henry Rossi, Malte Oppermann, Benjamin Bauer

The measurement of chirality and its temporal evolution are crucial for the understanding of a large range of biological functions and chemical reactions. Steady-state circular dichroism (CD) is a standard analytical tool for measuring chirality in chemist ...

OPTICAL SOC AMER2019

From model to radar variables: a new forward polarimetric radar operator for COSMO

Alexis Berne, Daniel Wolfensberger

In this work, a new forward polarimetric radar operator for the COSMO numerical weather prediction (NWP) model is proposed. This operator is able to simulate measurements of radar reflectivity at horizontal polarization, differential reflectivity as well a ...

Copernicus GmbH2018

Linearly polarized GHz magnetization dynamics of spin helix modes in the ferrimagnetic insulator Cu_2OSeO_3

Helmuth Berger, Dirk Grundler

Linear dichroism — the polarization dependent absorption of electromagnetic waves— is routinely exploited in applications as diverse as structure determination of DNA or polarization filters in optical technologies. Here filamentary absorbers with a large ...

Nature Research2017