Publications associées à Near-field polarization measurements based on two arbitrary, orthogonal optical field components

Wandering principal optical axes in van der Waals triclinic materials

Nature is abundant in material platforms with anisotropic permittivities arising from symmetry reduction that feature a variety of extraordinary optical effects. Principal optical axes are essential characteristics for these effects that define light-matte ...

Nature Portfolio2024

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

Nonlinear Frequency Conversion in III-Nitride Doubly Resonant Photonic Crystal Cavities

Jun Wang

Nonlinear frequency conversion processes, such as second-harmonic generation (SHG) and spontaneous parametric down-conversion (SPDC), are essential in many applications, including the generation of entangled photons. It's desirable to enhance these process ...

EPFL2023

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

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

Structured light engineering using a photonic nanojet

Toralf Scharf, Maryam Yousefi, Daniel Necesal

In this Letter, we present the photonic nanojet as a phenomenon in a structured light generator system that is implemented to modify the source focal spot size and emission angle. The optical system comprises a microlens array that is illuminated by a focu ...

OPTICAL SOC AMER2021

Structured light generation by refractive-diffractive micro optical array illuminators

Maryam Yousefi

Structured light generation having broad applications in different optical fields, is the topic of this thesis. Our structured light generation strategy is based on applying periodic microoptical elements at the refraction-diffraction limit, under a focuse ...

EPFL2021

Depth of field extension through polarization aberrations

Alessandro Grosso

This paper focuses on depth of field (DOF) extension through polarization aberrations. The addition of polarizing elements into an optical system allows to exploit the polarization of the incoming light as an additional degree of freedom in the optical sys ...

SPIE-INT SOC OPTICAL ENGINEERING2019

EM Fields Generated by a Scale Model Helical Antenna and Its Use in Validating a Code for Lightning-Induced Voltage Calculation

Farhad Rachidi-Haeri

This paper aims at validating a code for the evaluation of lightning-induced overvoltages developed in the PSCADEMTDC environment using experimental results obtained on an experimental facility deployed at the University of S˜ao Paulo, Brazil that emulates ...

2019

Parallel integro-differential equation solving via multi-channel reciprocal bianisotropic metasurface augmented by normal susceptibilities

Karim Achouri, Ali Momeni

Analog optical signal processing has dramatically transcended the speed and energy limitations accompanied with its digital microelectronic counterparts. Motivated by recent metasurface?s evolution, the angular scattering diversity of a reciprocal passive ...

2019

Near-field characterization of Bloch surface waves based 2D optical components

Richa Dubey

Bloch surface waves (BSWs) are surface electromagnetic modes that propagate at the interface between a multilayer substrate and a homogeneous external medium. The optical field of the surface mode is confined near the surface of the multilayer. This vertic ...

EPFL2017

Characterization methodology for lead zirconate titanate thin films with interdigitated electrode structures

Paul Muralt, Robin Nigon, Trygve Magnus Raeder

The accurate evaluation of ferroelectric thin films operated with interdigitated electrodes is quite a complex task. In this article, we show how to correct the electric field and the capacitance in order to obtain identical polarization and CV loops for a ...

Amer Inst Physics2017

3D-printed Ka-band Antenna Based on Stereolithography

Juan Ramon Mosig, Joana Rita Alves dos Santos Silva, Tomislav Debogovic, Maria Garcia Vigueras

This paper presents a circularly-polarized dual-band antenna for Ka-band satellite communications which operates simultaneously in both civil and military downlink (17.7-21.2 GHz) and uplink (27.5-31 GHz) bands. The antenna is composed of a metallic ridged ...

IEEE2017

Highly-sensitive distributed birefringence measurements based on a two-pulse interrogation of a dynamic Brillouin grating

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Andrey Denisov

A method for distributed birefringence measurements is proposed based on the interference pattern generated by the interrogation of a dynamic Brillouin grating (DBG) using two short consecutive optical pulses. Compared to existing DBG interrogation techniq ...

Ieee2017

Coherent Rayleigh time domain reflectometry : novel applications for optical fibre sensing

Xin Lu

Owing to the advantages of the optical fibre, such as lightweight, small size, low cost and immunity to electromagnetic interferences, the fibre sensors have been applied in diverse fields and the scientific research on fibre sensing keeps improving to mee ...

EPFL2016

Method and apparatus for measuring the local birefingence along an optical waveguide

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Xin Lu

This invention relates to a system and method to determine the distributed birefringence profile along an optical fibre. Birefringence manifests as different refractive indices for two orthogonal states of polarization of the light propagating in the optic ...

2016

Novel technique for distributed fibre sensing based on coherent Rayleigh scattering measurements of birefringence

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Xin Lu

A novel distributed fibre sensing technique is described and experimentally validated, based on birefringence measurements using coherent Rayleigh scattering. It natively provides distributed measurements of temperature and strain with more than an order o ...

Spie-Int Soc Optical Engineering2016

Contribution of spontaneous polarization and its fluctuations to refraction of light in ferroelectrics

Alexander Tagantsev

The expressions for the spontaneous polar contribution delta n (i) (s) to the principal values of the refractive index due to the quadratic electro-optic effect in ferroelectrics have been considered within the phenomenological approach taking into account ...

Maik Nauka/Interperiodica/Springer2016