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Concept

Intensity (physics)

Publications associées (25)

Spatial statistics of superposition of two uncorrelated speckle patterns with polarization diversity

Abhijit Roy

A detailed theoretical and experimental study on the effect of the superposition of uncorrelated speckle patterns with polarization diversity on the spatial statistics of the superposed speckle pattern is presented. It is shown that depending on the mutual ...

Elsevier2021

3D reconstruction of weakly scattering objects from 2D intensity-only measurements using the Wolf transform

Demetri Psaltis, Joowon Lim

A new approach to optical diffraction tomography (ODT) based on intensity measurements is presented. By applying the Wolf transform directly to intensity measurements, we observed unexpected behavior in the 3D reconstruction of the sample. Such a reconstru ...

2021

Improvement of Mott spin polarimeters: An overlooked redundancy

Mauro Fanciulli

In Mott polarimeters, the measurement of the spin polarization of an electron beam along two perpendicular quantization axes is commonly performed by collecting scattered electrons with four independent detectors placed azimuthally at 90 degrees from each ...

2020

Actor neural networks for the robust control of partially measured nonlinear systems showcased for image propagation through diffuse media

Demetri Psaltis, Christophe Moser, Damien Claude-Marie Loterie, Eirini Kakkava, Babak Rahmani, Ugur Tegin, Navid Borhani

The output of physical systems, such as the scrambled pattern formed by shining the spot of a laser pointer through fog, is often easily accessible by direct measurements. However, selection of the input of such a system to obtain a desired output is diffi ...

SPRINGERNATURE2020

Brillouin scattering in gas-filled hollow-core fibres

Flavien Gyger

Edward E. Hagenlocker and William G. Rado demonstrated Brillouin interaction in gas for the first time in 1965, right after the very first demonstrations of stimulated Brillouin scattering in solid materials. In their experiment, they used a megawatt pulse ...

EPFL2020

Level-line moirés by superposition of cylindrical microlens gratings

Jürgen Brugger, Roger Hersch, Valentin Flauraud, Thomas Walger, Théophane Besson

Two superposed layers of transparent cylindrical lenslet gratings create classical moiré fringes when illuminated from behind. We rely on this observation to conceive special devices made of superposed lenslet gratings that produce compelling beating shape ...

2020

Inverse Analysis of Radiative Flux Maps for the Characterization of High Flux Sources

Sophia Haussener, Clemens Gregor Suter, Gaël Jean Clément Levêque

The reconstruction of the angular and spatial intensity distribution from radiative flux maps measured in high flux solar simulators or optical concentrators is an ill-posed inverse problem requiring special solution strategies. We aimed at providing a sol ...

2019

A field study investigation on the influence of light level on subjective thermal perception in different seasons

Marilyne Andersen, Jan Wienold, Giorgia Chinazzo, Luisa Pastore

This paper evaluates the influence of light levels (i.e., illuminance) on subjective thermal perception of people, distinguishing between thermal sensation and thermal evaluation. The goal is to investigate whether reported effects found by other studies i ...

NCEUB 20182018

Light-driven model for identifying indicators of non-visual health potential in the built environment

María Lovísa Ámundadóttir

This thesis introduces a new approach to characterize and evaluate ocular light exposure based on the discovery of novel blue light-sensitive photoreceptors in the human eye. These photoreceptors are the primary mediators of 'non-visual' responses impactin ...

EPFL2016

Energy-selective neutron imaging for materials science

Steven Luc X Peetermans

Common neutron imaging techniques study the attenuation of a neutron beam penetrating a sample of interest. The recorded radiograph shows a contrast depending on traversed material and its thickness. Tomography allows separating both and obtaining 3D spati ...

EPFL2015

Simultaneous measurement of in-plane and out-of-plane displacements using pseudo-Wigner-Hough transform

Pramod Rastogi, Rishikesh Dilip Kulkarni

A new method based on pseudo-Wigner-Hough transform is proposed for the simultaneous measurement of the in-plane and out-of-plane displacements using digital holographic moire. Multiple interference phases corresponding to the in-plane and out-of-plane dis ...

Optical Society of America2014

Oversampled Noisy Binary Image Sensor

Martin Vetterli, Feng Yang

We study the oversampled binary image sensor in [1] under noisy scenario. The binary image sensor is similar to traditional photographic film with pixel value equal to "0" or "1". The potential application of the oversampled binary image sensor is high dyn ...

Ieee2013

A deep-blue emitting charged bis-cyclometallated iridium(III) complex for light-emitting electrochemical cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Rosario Scopelliti

We report here a new cationic bis-cyclometallated iridium(III) complex, 1, with deep-blue emission at 440 nm and its use in Light-emitting Electrochemical Cells (LECs). The design is based on the 2',6'-difluoro-2,3'-bipyridine skeleton as the cyclometallat ...

Royal Society of Chemistry2013

Full field vertical scanning in short coherence digital holographic microscope

Christian Depeursinge, Christophe Moser, Etienne Cuche, Frédéric Montfort

In Digital holography Microscopes (DHM) implemented in the so-called "off axis" configuration, the object and reference wave fronts are not co-planar but form an angle of a few degrees. This results into two main drawbacks. First, the contrast of the inter ...

Optical Soc Amer2013

High Intensity Beam Issues in the CERN Proton Synchrotron

Sandra Aumon

This PhD work is about limitations of high intensity proton beams observed in the CERN Proton Synchrotron (PS) and, in particular, about issues at injection and transition energies. With its 53 years, the CERN PS would have to operate beyond the limit of i ...

EPFL2012

Bits from Photons : Oversampled Binary Image Acquisition

Feng Yang

The trends in the design of image sensors are to build sensors with low noise, high sensitivity, high dynamic range, and small pixel size. How can we benefit from pixels with small size and high sensitivity? In this dissertation, we study a new image senso ...

EPFL2012

Cellular Dynamics and Three-Dimensional Refractive Index Distribution Studied with Quantitative Phase Imaging

Nicolas Pavillon

We present in this PhD thesis work various applications of digital holographic microscopy (DHM), an imaging technique based on coherent illumination which enables the recovery of the full complex wavefront, i.e. the amplitude and phase of a wave field whic ...

EPFL2011

Image Reconstruction in the Gigavision Camera

Edoardo Charbon, Martin Vetterli, Sabine Süsstrunk, Luciano Sbaiz, Feng Yang

Recently we have proposed a new image device called the gigavision camera. The main feature of this camera is that the pixels have a binary response. The response function of a gigavision sensor is non-linear and similar to a logarithmic function, which ma ...

2009

Theoretical Investigation of Iterative Phase Retrieval Algorithm for Quasi-Optical Millimeter-Wave RF Beams

Stefano Alberti, Jean-Philippe Hogge

In this paper, we present a detailed analysis of the iterative phase retrieval approach (TPRA) for determining the phase profile of the output microwave beam of a gyrotron from known intensity patterns emphasizing the field propagation techniques which are ...

IEEE2009

Infrared Measurements of the RF Output of 170-GHz/2-MW Coaxial Cavity Gyrotron and Its Phase Retrieval Analysis

Timothy Goodman, Stefano Alberti, Jean-Philippe Hogge

We report the experimental results of the infrared measurements of output RF beam of the European 2-MW 170-GHz coaxial cavity gyrotron for ITER. The output beam profile is measured by the infrared thermographic technique using an infrared camera and a targ ...

2009