Publications related to Long-distance distributed pressure sensing based on frequency-scanned phase-sensitive optical time-domain reflectometry

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

Ultralong 100 ns spin relaxation time in graphite at room temperature

László Forró, Bálint Náfrádi, Péter Szirmai, Bence Gábor Márkus

Graphite has been intensively studied, yet its electron spins dynamics remains an unresolved problem even 70 years after the first experiments. The central quantities, the longitudinal (T-1) and transverse (T-2) relaxation times were postulated to be equal ...

Nature Portfolio2023

How to improve the efficiency of a traditional dissolution dynamic nuclear polarization (dDNP) apparatus: Design and performance of a fluid path compatible dDNP/LOD-ESR probe

Jean-Noël Hyacinthe, Andrea Capozzi, Thanh Phong Kevin Lê

Dissolution Dynamic Nuclear Polarization (dDNP) was invented almost twenty years ago. Ever since, hardware advancement has observed 2 trends: the quest for DNP at higher field and, more recently, the development of cryogen free polarizers. Despite the DNP ...

Academic Press Inc - Elsevier Science2022

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

Performance and reproducibility of C-13 and N-15 hyperpolarization using a cryogen-free DNP polarizer

Hikari Ananda Infinity Yoshihara, Arianna Ferrari

The setup, operational procedures and performance of a cryogen-free device for producing hyperpolarized contrast agents using dissolution dynamic nuclear polarization (dDNP) in a preclinical imaging center is described. The polarization was optimized using ...

Nature Portfolio2022

Sensing of Surface and Bulk Refractive Index Using Magnetophotonic Crystal with Hybrid Magneto-Optical Response

Serguei Sekatski

We propose an all-dielectric magneto-photonic crystal with a hybrid magneto-optical response that allows for the simultaneous measurements of the surface and bulk refractive index of the analyzed substance. The approach is based on two different spectral f ...

2021

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

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

Distributed hydrostatic pressure measurement using phase OTDR in a highly birefringent photonic crystal fiber

Luc Thévenaz, Li Zhang

Although distributed fiber-optic sensing of axial strain and temperature is a well-established technique, there are almost no demonstrations of distributed hydrostatic pressure sensing. The main obstacle for such measurements is the low sensitivity to pres ...

IEEE Institute of Electrical and Electronics Engineers2019

Generalized Optical Signal Processing Based on Multioperator Metasurfaces Synthesized by Susceptibility Tensors

Karim Achouri, Ali Momeni

This paper theoretically proposes a multichannel nonlocal metasurface computer characterized by generalized sheet transition conditions (GSTCs) and surface susceptibility tensors. The study explores polarization- and angle-multiplexed metasurfaces enabling ...

American Physical Society (APS)2019

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

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

Tailored-Potential Semiconductor Quantum Nanostructures Grown in Inverted Pyramids

Mikhail Lazarev

We have focused on the ability to tune the aluminum (Al) content of the AlGaAs alloy along the growth direction in inverted pyramids (by MOVPE), thus tailoring the potential along a QWR nanostructure. Three parabolic-potential QDs (PQDs) of different poten ...

EPFL2019

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

Cyanine platelet single crystals: growth, crystal structure and optical spectra

Frank Nüesch, Antonia Neels, Jakob Heier

Crystalline organic semiconducting materials are much in demand for multiple electronic and optoelectronic device applications. Here, solution grown ultrathin rhombic crystals of a trimethine carbocyanine anionic dye are used to establish relationships bet ...

Royal Society of Chemistry2018

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

Charge screening strategy for domain pattern control in nano-scale ferroelectric systems

Nava Setter, Tomas Sluka

Strain engineering is a widespread strategy used to enhance performance of devices based on semiconductor thin films. In ferroelectrics strain engineering is used to control the domain pattern: When an epitaxial film is biaxially compressed, e.g. due to la ...

Nature Research2017

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