Publications related to Reflectance

Quantification of the Phenomena Affecting Reflective Arterial Photoplethysmography

Nikolaos Stergiopoulos, Georgios Rovas, Vasiliki Bikia

Photoplethysmography (PPG) is a widely emerging method to assess vascular health in humans. The origins of the signal of reflective PPG on peripheral arteries have not been thoroughly investigated. We aimed to identify and quantify the optical and biomecha ...

MDPI2023

Method for operating a frequency agile tunable self-injection locking laser system and self-injection locking laser system

Tobias Kippenberg, Anat Siddharth, Grigorii Likhachev

The invention relates to a Method for operating a frequency agile tunable self-injection locking laser system being formed by a laser device coupled to at least one optical resonator, wherein a diode current of a laser diode of the laser device is controll ...

2023

Pitfalls in the spectral measurements of polarization-altering metasurfaces

Olivier Martin, Hsiang-Chu Wang

The optical characterization of metasurfaces and nanostructures that alter the polarization of light is tricky and can lead to unphysical results, such as reflectance beyond unity. We track the origin of such pitfalls to the response of some typical optica ...

Optica Publishing Group2022

Reflectivity of Venus's Dayside Disk During the 2020 Observation Campaign: Outcomes and Future Perspectives

Stephan Hellmich

We performed a unique Venus observation campaign to measure the disk brightness of Venus over a broad range of wavelengths in 2020 August and September. The primary goal of the campaign was to investigate the absorption properties of the unknown absorber i ...

IOP Publishing Ltd2022

Lippmann Photography: A Signal Processing Perspective

Martin Vetterli, Arnaud Latty, Adam James Scholefield, Gilles Baechler, Michalina Wanda Pacholska

Lippmann (or interferential) photography is the first and only analog photography method that can capture the full color spectrum of a scene in a single take. This technique, invented more than a hundred years ago, records the colors by creating interferen ...

2022

Electrical transport properties of Ru1-xTixO2 films deposited by magnetron sputtering technique

Rosendo Sanjines, Silviu Cosmin Sandu

The optical and electrical properties of Ru1-xTixO2 (0

PERGAMON-ELSEVIER SCIENCE LTD2021

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

Light Path Gradients for Forward and Inverse Rendering

Tizian Lucien Zeltner

Physically based rendering is a process for photorealistic digital image synthesis and one of the core problems in computer graphics. It involves simulating the light transport, i.e. the emission, propagation, and scattering of light through a virtual scen ...

EPFL2021

Science's Response to CoVID-19

Yimon Aye

CoVID-19 is a multi-symptomatic disease which has made a global impact due to its ability to spread rapidly, and its relatively high mortality rate. Beyond the heroic efforts to develop vaccines, which we do not discuss herein, the response of scientists a ...

WILEY-V C H VERLAG GMBH2021

On the Complete Radiation Pattern of a Vertical Hertzian Dipole Above a Low-Loss Ground

Krzysztof Michalski, Juan Ramon Mosig

The complete radiation field pattern of a vertical Hertzian dipole antenna on or above a lossless or low-loss dielectric half-space is studied using a rigorous Sommerfeld formalism. The reflected fields in the air above the interface and the subsurface fie ...

Ieee-Inst Electrical Electronics Engineers Inc2021

Effects of multiple scattering on angle-independent structural color in disordered colloidal materials

Sofia Magkiriadou

Disordered packings of colloidal spheres show angle-independent structural color when the particles are on the scale of the wavelength of visible light. Previous work has shown that the positions of the peaks in the reflectance spectra can be predicted acc ...

AMER PHYSICAL SOC2020

Slope-Space Integrals for Specular Next Event Estimation

Wenzel Alban Jakob, Tizian Lucien Zeltner, Guillaume Rémi Bruno Loubet

Monte Carlo light transport simulations often lack robustness in scenes containing specular or near-specular materials. Widely used uni- and bidirectional sampling strategies tend to find light paths involving such materials with insufficient probability, ...

ASSOC COMPUTING MACHINERY2020

Ultra-Broadband and Omnidirectional Perfect Absorber Based on Copper Nanowire/Carbon Nanotube Hierarchical Structure

Giulia Tagliabue, Fateme Kiani Shahvandi, Theodoros Tsoulos

Zero reflection and complete light absorption are required in a wide range of applications ranging from sensing devices to solar heaters and photoelectrodes. However, simultaneously satisfying the requirements of the broadband spectrum, omnidirectionality, ...

AMER CHEMICAL SOC2020

Blue-shift ultrasensitivity using rhombus-shaped plasmonic crystal on Si3N4 membrane

Bahareh Ghadiani, Dordaneh Etezadi, Yasaman Jahani, Ershad Mohammadi, Foziyeh Sohrabi, Mahdi Tamizifar

Harnessing ultrasensitivity from optical structures to detect tiny changes in the targeted samples is the main goal of scientists in the field of sensor design. In this study, an uncommon rhombus-shape plasmonic structure is proposed for providing blue-shi ...

OPTICAL SOC AMER2020

Precise and accurate image-based measurements of optical material properties

Marjan Shahpaski

The appearance of objects is governed by how they reflect, transmit and absorb the light they receive. That, in turn, depends on the material's internal structure, surface structure, and viewing and illumination directions. Changes in those characteristics ...

EPFL2020

Single crystal diamond gain mirrors for high performance vertical external cavity surface emitting lasers

Niels Quack, Grigore Suruceanu, Gergely Huszka, Alexandru Mereuta, Andrei Caliman, Pascal Gallo, Mehdi Naamoun

We report on the design, fabrication and optical performance of gain mirrors in single crystal diamond substrates for vertical external cavity surface emitting lasers (VECSELs). VECSELs have gained attention recently due to their potential for high emissio ...

2020

Practical Product Path Guiding Using Linearly Transformed Cosines

Wenzel Alban Jakob

Path tracing is now the standard method used to generate realistic imagery in many domains, e.g., film, special effects, architecture etc. Path guiding has recently emerged as a powerful strategy to counter the notoriously long computation times required t ...

WILEY2020

A Politics of Intellectual Property: Creating a Patent System in Revolutionary France

Jérôme Baudry

Economic interpretations, in particular the lens of the Industrial Revolution, have strongly influenced our understanding of the rise of intellectual property. This article examines the political origins of the 1791 patent law in France, which is usually s ...

2020

First mirror test in JET for ITER: Complete overview after three ILW campaigns

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

Wide Gamut Spectral Upsampling with Fluorescence

Wenzel Alban Jakob

Physically based spectral rendering has become increasingly important in recent years. However, asset textures in such systems are usually still drawn or acquired as RGB tristimulus values. While a number of RGB to spectrum upsampling techniques are availa ...

2019