Publications related to Optical properties

Tuning the Solar Performance of Building Facades through Polymer 3D Printing: Toward Bespoke Thermo-Optical Properties

Stephen William Wasilewski, Arno Schlueter

Facades are the primary interface controlling the flow of solar energy in buildings and affecting their energy balance and environmental impact. Recently, large-scale 3D printing (3DP) of translucent polymers has been explored as a technique for fabricatin ...

Wiley2023

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

Optical properties and photochemical production of hydroxyl radical and singlet oxygen after ozonation of dissolved organic matter

Urs von Gunten, Frank Jonathan Leresche

This study focuses on the effects of ozonation on the optical and photochemical properties of dissolved organic matter (DOM). Upon ozonation, a decrease in light absorption properties of DOM was observed concomitantly with a large increase in singlet oxyge ...

ROYAL SOC CHEMISTRY2021

Probing intraband excitations in ZrTe5: A high-pressure infrared and transport study

Helmuth Berger, Mathieu François Padlewski, Philip Johannes Walter Moll, Matthias Carsten Putzke, Ana Akrap, Edoardo Martino

Zirconium pentatetelluride, ZrTe5, shows remarkable sensitivity to hydrostatic pressure. In this work we address the high-pressure transport and optical properties of this compound, on samples grown by flux and chemical vapor transport. The high-pressure r ...

2020

Teaching optics to a machine learning network

Olivier Martin, André-Pierre Blanchard-Dionne

In this Letter, we demonstrate how harmonic oscillator equations can be integrated in a neural network to improve the spectral response prediction for an optical system. We use the optical properties of a one-dimensional nanoslit array for a practical impl ...

2020

Comparative analysis of transmittance measurement geometries and apparatus

Sabine Süsstrunk, Marjan Shahpaski

The accurate measurement of reflectance and transmittance properties of materials is essential in the printing and display industries in order to ensure precise color reproduction. In comparison with reflectance measurement, where the impact of different g ...

2019

Spin-valley optoelectronics based on two-dimensional materials

Dmitrii Unuchek

Two-dimensional (2D) materials, in particular graphene and transition metal dichalcogenides (TMDC), have attracted great scientific interest over the last decade, revealing exceptional mechanical, electrical and optical properties. Owing to their layered n ...

EPFL2019

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

Radiative characterization of random fibrous media with optically large long cylindrical fibers

Sophia Haussener

Radiative heat transfer is analyzed in participating media consisting of long cylindrical fibers with a diameter in the limit of geometrical optics. The absorption and scattering coefficients and the scattering phase function of the medium are determined b ...

Elsevier2017

Pressure Tuning of the Optical Properties of GaAs Nanowires

Anna Fontcuberta i Morral, Emanuele Uccelli

The tuning of the optical and electronic properties of semiconductor nanowires can be achieved by crystal phase engineering. Zinc-blende and diamond semiconductors exhibit pressure-induced structural transitions as well as a strong pressure dependence of t ...

American Chemical Society2012

Accordabilité de la réponse optique des cristaux photoniques par infiltration de matériaux organiques

Pascale El-Kallassi

Photonic crystals are stuctures in which the refractive index varies periodically on the wavelength scale in one, two or three dimensions. Due to interference effects, these structures can forbid light propagation over a large spectral range called "the ph ...

EPFL2009

Microlenses on Bragg Reflectors to Create Iridescent Colors

Hans Peter Herzig, Toralf Scharf

In nature strong colors play an important role in scaring away predators or finding a mate. Often, the strongest and brightest colors arise from coherent scattering and reflection on periodic structures on a length scale of several micro- or nanometers. Un ...

2008

Effects of upstream hydropower operation and oligotrophication on the light regime of a turbid peri-alpine lake

Alfred Johny Wüest

Anthropogenic activities in catchments can alter the light regimes in downstream natural waters, affecting light attenuation and the perceived optical properties of the waters. We analyzed the effects of upstream hydropower operation and oligotrophication ...

Birkhauser Verlag Ag2007

Compositional model for predicting multilayer reflectances and transmittances in color reproduction

Mathieu Hébert

The color of materials such as paints, prints and glass may be characterized by a reflectance or a transmittance spectrum. Modeling their reflectance and their transmittance requires describing the interaction of light, from the light source to the observe ...

EPFL2006

Étude expérimentale des propriétés optiques des cristaux photoniques bidimensionnels et de leur accordabillité

Barbara Wild

Photonic crystals are periodic dielectric structures, where the periodicity varies in one, two or three dimensions. Analogous to the periodic potential of electrons in semiconductors, the periodic variation of the dielectric constant influences the electro ...

EPFL2006

Etude et réalisation de cristaux photoniques pour l'optique intégrée

Benoît Lombardet

Photonic crystals are periodic dielectric structures, where the periodicity varies on the wavelength scale. Analogous to electrons in semiconductors, the photon propagation can be described using a band structure in which transmission bands are separated b ...

EPFL2005

Optical properties of In(Ga)As/GaAs quantum dot-based devices emitting at 1.3[mu]m

Self-assembled quantum-dots (QDs) represent a distributed ensemble of zero dimensional structures with a near-singular density of states. Implemented as the active medium in a diode laser their unique properties lead to improved and often novel characteris ...

EPFL2004

Optical spectral probing for epithelial tissue characterisation

Philippe Thueler

In this thesis, a new method has been developed, which determines the optical coefficients spectra (absorption and scattering) of small volumes of tissue (1 mm3) by the measurement of spatially resolved reflectance between 480 and 950 nm. Firstly, an algor ...

EPFL2001

3D optical diffraction tomography in thick highly scattering media using diffuse photon density waves

Near InfraRed (NIR) frequency-domain techniques are promising clinical imaging tools, due to their ability in providing metabolic information about healthy and cancerous abnormalities (tumours, cysts, haematomas, etc.) embedded in thick biological highly d ...

EPFL2000

Three-dimensional optical phantom and its application in photodynamic therapy

Hubert van den Bergh, Georges Wagnières

BACKGROUND AND OBJECTIVE: A technique to manufacture a stable, reproducible three-dimensional optical phantom is presented. This phantom reproduces the tissue's optical properties as well as the geometry and, to some extent, the mechanical properties of th ...

1997