Publications associées à Dichroism

Hard X-ray helical dichroism of disordered molecular media

Majed Chergui, Giulia Fulvia Mancini, Malte Oppermann, Camila Bacellar Cases Da Silveira, Dominik Kinschel, Oliviero Cannelli, Christian David, Jérôme Lacour

Chirality is a structural property of molecules lacking mirror symmetry that has strong implications in diverse fields, ranging from life sciences to materials science. Chirality-sensitive spectroscopic methods, such as circular dichroism, exhibit weak sig ...

Nature Publishing Group2022

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

Terahertz-optical properties of a bismuth ferrite single crystal

Henrik Moodysson Rønnow, Jean-Philippe Ansermet, Marcin Bialek

Transmission through a (100)-oriented single crystal of bismuth ferrite (BiFeO3) was studied at frequencies of 0.485-0.765 THz with a continuous-wave source and in the temperature range of 30-350 K as a function of polarization angle. The fine splitting of ...

2019

Broad-Band Ultraviolet CD Spectroscopy of Ultrafast Peptide Backbone Conformational Dynamics

Majed Chergui, Malte Oppermann, Benjamin Bauer

The far-UV spectral window widely used for the conformational analysis of biomolecules is not easily covered with broad-band lasers. This has made it difficult to use circular dichroism (CD) spectroscopy to directly follow fast structure changes. By combin ...

AMER CHEMICAL SOC2019

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

X-ray absorption linear dichroism at the Ti K edge of anatase TiO2 single crystals

Majed Chergui, Giulia Fulvia Mancini, Thomas Charles Henry Rossi, Camila Bacellar Cases Da Silveira, Dominik Kinschel, Oliviero Cannelli, Jérémy Raymond Jean Maurice Rouxel

Anatase TiO2 (a-TiO2) exhibits a strong x-ray absorption linear dichroism in the pre-edge, the XANES and the EXAFS at the titanium K edge. In the pre-edge region, the behavior of the A1-A3 and B peaks originating from the 1s - 3d transitions is due to the ...

2019

Instrumentation for the upgrade to the JET core charge-exchange spectrometers

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Martinus Gijs, Jonathan Graves, Yves Martin, Duccio Testa, Patrick Blanchard, Bruno Emanuel Ferreira De Sousa Correia, Alessandro Pau, Pierre-Thomas Paul Brun, Cristian Sommariva, Henri Weisen, Richard Pitts, Sun Hee Kim, Yann Camenen, Jan Horacek, Javier García Hernández, Marco Wischmeier, Mikhail Maslov, Nicola Vianello, Miguel Fernández Ruiz, Federico Nespoli, Antonio José Pereira de Figueiredo, Liang Yao, Yao Zhou, David Pfefferlé, Dalziel Joseph Wilson, Robin Humphry-Baker, Davide Galassi, José Pedro Rebelo Ferreira Marques, Ana Francisca Leal Silva Soares, Jonathan Marc Philippe Faustin, Daniel Scott Alessi, Arnout Lodewijk M Beckers, Julio Rodriguez, Hamish William Patten, Jonnathan Cesar Hidalgo Acosta, Samuel Lanthaler, , , , , , , ,

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

Dirk Grundler, Helmuth Berger

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

Strongly Red-Shifted Photoluminescence Band Induced by Molecular Twisting in Cyanine (Cy3) Dye Films

Frank Nüesch, Roland Hany, Jakob Heier, Surendra Babu Anantharaman, Chuyao Peng

Cyanine dye molecules, used as monomers or in aggregate form, find interesting applications in optoelectronic devices. Among the various aggregate species incorporating organic dyes, centrosymmetric dimers are known as nonluminescent. They can act as excit ...

American Chemical Society2017

Multifunctional Plasmonic Metasurfaces for Novel Spectral and Spatial Applications

Chen Yan

Intensive developments of plasmonic nanomaterials over recent decades have inspired appealing applications in biosensing, optical trapping, fluorescence enhancement and light harvesting in solar cells. These nanostructures supporting unique light-matter in ...

EPFL2017

Optofluidic-tunable color filters and spectroscopy based on liquid-crystal microflows

Demetri Psaltis, Andreas Vasdekis, Julien Cuennet

The integration of color filters with microfluidics has attracted substantial attention in recent years, for on-chip absorption, fluorescence, or Raman analysis. We describe such tunable filters based on the micro-flow of liquid crystals. The filter operat ...

Royal Society of Chemistry2013

Graphene Sublattice Symmetry and Isospin Determined by Circular Dichroism in Angle-Resolved Photoemission Spectroscopy

Klaus Kern, Isabella Gierz

The Dirac-like electronic structure of graphene originates from the equivalence of the two basis atoms in the honeycomb lattice. We show that the characteristic parameters of the initial state wave function (sublattice symmetry and isospin) can be determin ...

Amer Chemical Soc2012

X-Treme beamline at SLS: X-ray magnetic circular and linear dichroism at high field and low temperature

Harald Brune, Stefano Rusponi, Jan Gui-Hyon Dreiser, Thomas Schmidt

X-Treme is a soft X-ray beamline recently built in the Swiss Light Source at the Paul Scherrer Institut in collaboration with Ecole Polytechnique Federale de Lausanne. The beamline is dedicated to polarization-dependent X-ray absorption spectroscopy at hig ...

Wiley-Blackwell2012

Magnetic circular dichroism in electron energy loss spectrometry

Cécile Hébert

The measurement of circular dichroism in the electron microscope is a new, emerging method and, as such, it is subject to constant refinement and improvement. Different ways can be envisaged to record the signal. We present an overview of the key steps in ...

2008

Linear dichroism of CdSe nanodots: Large anisotropy of the band-gap absorption induced by ground-state dipole moments

Majed Chergui, Frank van Mourik

The authors measured the elec. field induced linear dichroism for a wide range of sizes of CdSe nanocrystals. Large ground-state dipole moments were obsd., esp. for the smallest crystals. In these, the authors found a very large anisotropy of the absorptio ...

2008

Polarization dependence of electroluminescence from closely-stacked and columnar quantum dots

Marco Rossetti, Philipp Ridha

Quantum dots (QDs) have a potential for application in semiconductor optical amplifiers (SOAs), due to their high saturation power related to the low differential gain, fast gain recovery and wide gain spectrum compared to quantum wells. Besides all advant ...

Springer US2008

Excited excitonic states observed in semiconductor quantum dots using polarization resolved optical spectroscopy

Elyahou Kapon, Alok Rudra, Daniel Oberli, Valentina Troncale

We present results on the polarization-resolved photoluminescence emitted from InGaAs/AlGaAs single quantum dots (QDs) grown in inverted tetrahedral pyramids. The emitted light was detected for two mutually perpendicular linear polarization directions in t ...

American Institute of Physics2007

Optical polarization anisotropy and hole states in pyramidal quantum dots

Elyahou Kapon, Alok Rudra, Daniel Oberli, Valentina Troncale

The authors present a polarization-resolved photoluminescence study of single semiconductor quantum dots (QDs) interconnected to quantum wires, measured both in a top geometry, and in a less conventional cleaved-edge geometry. Strong polarization anisotrop ...

AIP American Institute of Physics2006