Publications related to Spectrum

Engineering Absorption for Foil Applications

Light matter interactions such as extinction, reflection, and transmission can be described by classical optics. Dur-ing the past decades, research focused on a novel resonant extinction type called plasmonics that allows for en-hancement of both types of ...

EPFL2022

Roadmap on multimode light shaping

Tobias Kippenberg, Jérôme Faist, Marco Piccardo

Our ability to generate new distributions of light has been remarkably enhanced in recent years. At the most fundamental level, these light patterns are obtained by ingeniously combining different electromagnetic modes. Interestingly, the modal superpositi ...

IOP Publishing Ltd2022

Alertness in work environments : on the role of indoor daylight exposure

Victoria Eugenia Soto Magán

Light enables to see the world around us, while playing a key role in our biological functioning. During the last decades, light has become an important research topic for chronobiologists and neuroscientists, and their findings are increasingly interwoven ...

EPFL2021

Image-Based Acquisition and Modeling of Polarimetric Reflectance

Wenzel Alban Jakob, Tizian Lucien Zeltner, Xin Tong

Realistic modeling of the bidirectional reflectance distribution function (BRDF) of scene objects is a vital prerequisite for any type of physically based rendering. In the last decades, the availability of databases containing real-world material measurem ...

ASSOC COMPUTING MACHINERY2020

Photovoltaic organic interface for neuronal stimulation in the near-infrared

Diego Ghezzi, Naïg Aurelia Ludmilla Chenais, Marta Jole Ildelfonsa Airaghi Leccardi, Laura Ferlauto, Elodie Geneviève Zollinger

Organic materials, such as conjugated polymers, are attractive building blocks for bioelectronic interfaces. In particular, organic semiconductors show excellent performance in light-mediated excitation and silencing of neuronal cells and tissues. However, ...

2020

Multichromatic calibration method and device

Dragos Constantin

A Multichromatic Calibration (MC) method of at least a spectral sensor which is one of a list comprising at least a spectrometer, a multispectral sensor, a hyperspectral sensor, a spectral camera, a color camera. The method comprises a. generating a plural ...

2019

Sampling the Multiple Facets of Light

Gilles Baechler

The theme of this thesis revolves around three important manifestations of light, namely its corpuscular, wave and electromagnetic nature. Our goal is to exploit these principles to analyze, design and build imaging modalities by developing new signal proc ...

EPFL2018

Visual Understanding of Light Absorption and Waveguiding in Standing Nanowires with 3D Fluorescence Confocal Microscopy

Anna Fontcuberta i Morral, Federico Matteini, Esther Alarcon Llado, Gözde Tütüncüoglu

Semiconductor nanowires are promising building blocks for next generation photonics. Indirect proofs of large absorption cross sections have been reported in nanostructures with subwavelength diameters, an effect that is even more prominent in vertically s ...

Amer Chemical Soc2017

Method to produce a full-color smoothed image

Sabine Süsstrunk

The present invention aims at providing a method to produce modified images of a human face while removing all defects, such as such as pigmentation irregularities (e.g., moles, freckles), irritation, roughness, or wrinkles This is achieved thanks to a met ...

2016

CSMA/CA in Time and Frequency Domains

Patrick Thiran, Julien Pierre Sacha Herzen

It has recently been shown that flexible channelization, whereby wireless stations adapt their spectrum bands on a per-frame basis, is feasible in practice. In this paper, we propose TF-CSMA/CA, an algorithm for flexible channelization that schedules packe ...

IEEE2015

Near-UV to red-emitting charged bis-cyclometallated iridium(III) complexes for light-emitting electrochemical cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Rosario Scopelliti, Davide Di Censo

Herein we report a series of charged iridium complexes emitting from near-UV to red using carbene-based (NC)-C-boolean AND: ancillary ligands. Synthesis, photophysical and electrochemical properties of this series are described in detail together with X-ra ...

Royal Society of Chemistry2012

Analysis of the low-frequency spectrum of the cubic noncentrosymmetric ferrimagnet Cu2OSeO3

Helmuth Berger

The IR reflectance spectra of the cubic noncentrosymmetric ferrimagnet Cu2OSeO3 (T-C approximate to 60 K) were investigated in the temperature range 10-80 K. Detailed analysis of the symmetry and composition of vibrational modes was conducted on the basis ...

2012

Ln(III)-cored complexes based on boron dipyrromethene (Bodipy) ligands for NIR emission

Jean-Claude Bünzli

Two Bodipy-based chromophores have been synthesized, which bear two methoxyphenyl substituents in the 1,7 positions and either hydrogen (L1) or bromine (L2) atoms in the 2,6 positions, with the aim of testing their ability to sensitize the luminescence of ...

2012

GUI-Aided NIR and Color Image Blending

Sabine Süsstrunk, Radhakrishna Achanta, Andrea Guidi

A near-infrared (NIR) image of a scene contains different information than the corresponding visible spectrum (RGB) image, due to physical phenomena related to scattering, absorption, and reflectance of the different radiation bands. It can be desirable to ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2010

Exploiting redundancy in color images

Joanna Marguier

The colors in a digital image do not only depend on the scene's reflectances, but also on the lighting conditions and on the characteristics of the imaging device. It is often necessary to separate the influence of these three elements, in particular to se ...

EPFL2010

Phosphorescent energy relay dye for improved light harvesting response in liquid dye-sensitized solar cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Jun Ho Yum

Energy transfer from phosphorescent ruthenium complex N877 dissolved in the liquid electrolyte to the squaraine sensitizer SQ1 anchored on the titanium oxide surface resulted in a four fold increase in external quantum efficiency in the blue part of the vi ...

Royal Society of Chemistry2010

Nanostructured surface fabricated by laser interference lithography to attenuate the reflectivity of microlens arrays

Hans Peter Herzig, Toralf Scharf, Pierre-Yves Baroni

A subwavelength-scale square lattice optical nanostructure is fabricated using an interference photolithography process on the surface of a quartz microlens array. This nanostructuring of the quartz surface introduces an antireflective effect, reducing ref ...

2010

Material Classification Using Color and NIR Images

Sabine Süsstrunk, Neda Salamati

Material classification is becoming more important in computer vision and digital photography applications, which require accurate classification of objects present in the imaged scene. This is a very challenging task because the sheer diversity of scene c ...

2009

Illuminant estimation and detection using near infrared

Sabine Süsstrunk

Digital camera sensors are sensitive to wavelengths ranging from the ultraviolet (200-400nm) to the near-infrared (700-100nm) bands. This range is, however, reduced because the aim of photographic cameras is to capture and reproduce the visible spectrum (4 ...

2009

Designing color filter arrays for the joint capture of visible and near-infrared images

Martin Vetterli, Sabine Süsstrunk, Yue Lu

Digital camera sensors are inherently sensitive to the near-infrared (NIR) part of the light spectrum. In this paper, we propose a general design for color filter arrays that allow the joint capture of visible/NIR images using a single sensor. We pose the ...

2009