Publications associées à Objectif de longue focale

Searching for Strong Gravitational Lenses

Frédéric Courbin, Cameron Alexander Campbell Lemon

Strong gravitational lenses provide unique laboratories for cosmological and astrophysical investigations, but they must first be discovered - a task that can be met with significant contamination by other astrophysical objects and asterisms. Here we revie ...

Springer2024

The impact of human expert visual inspection on the discovery of strong gravitational lenses

Frédéric Courbin, Benjamin Yvan Alexandre Clement, Eric Gérard Guy Paic, Hung-Hsu Chan, Martin Raoul Robert Millon, Karina Alexandra Rojas Olate, Rémy Elie Joseph, Elodie Marie Charlène Savary, Yue Pan

We investigate the ability of human 'expert' classifiers to identify strong gravitational lens candidates in Dark Energy Survey like imaging. We recruited a total of 55 people that completed more than 25 per cent of the project. During the classification t ...

OXFORD UNIV PRESS2023

Media Coverage of 3D Visual Tools Used in Urban Participatory Planning

Jens Ingensand, Thibaud Nicolas Chassin

The opportunities provided by adopting digitally-generated visual tools in urban participatory planning are compelling. These visual tools can promote interactions between authorities and citizens and among citizens. However, the urban participatory practi ...

IGI GLOBAL2023

Gravitationally lensed quasars in Gaia - IV. 150 new lenses, quasar pairs, and projected quasars

Frédéric Courbin, Aymeric Alexandre Galan, Cameron Alexander Campbell Lemon, Adriano Agnello

We report the spectroscopic follow-up of 175 lensed quasar candidates selected using Gaia Data Release 2 observations following Paper III of this series. Systems include 86 confirmed lensed quasars and a further 17 likely lensed quasars based on imaging an ...

OXFORD UNIV PRESS2023

The autoregressive neural network architecture of the Boltzmann distribution of pairwise interacting spins systems

Indaco Biazzo

Autoregressive Neural Networks (ARNNs) have shown exceptional results in generation tasks across image, language, and scientific domains. Despite their success, ARNN architectures often operate as black boxes without a clear connection to underlying physic ...

Nature Portfolio2023

Using wavelets to capture deviations from smoothness in galaxy-scale strong lenses

Frédéric Courbin, Aymeric Alexandre Galan, Georgios Vernardos, Austin Chandler Peel

Modeling the mass distribution of galaxy-scale strong gravitational lenses is a task of increasing difficulty. The high-resolution and depth of imaging data now available render simple analytical forms ineffective at capturing lens structures spanning a la ...

EDP SCIENCES S A2022

TOCOSMO VIII. A key test of systematics in the hierarchical method of time-delay cosmography

Frédéric Courbin

The largest source of systematic errors in the time-delay cosmography method likely arises from the lens model mass distribution, where an inaccurate choice of model could in principle bias the value of H-0. A Bayesian hierarchical framework has been propo ...

EDP SCIENCES S A2022

High-Resolution Multi-Spectral Imaging With Diffractive Lenses and Learned Reconstruction

Oguzhan Fatih Kar, Can Deniz Bezek

Spectral imaging is a fundamental diagnostic technique with widespread application. Conventional spectral imaging approaches have intrinsic limitations on spatial and spectral resolutions due to the physical components they rely on. To overcome these physi ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2021

Single-shot observation of breathers from noise-induced modulation instability using heterodyne temporal imaging

Alexey Tikan

We report phase and amplitude measurements of large coherent structures originating from the noise-induced modulation instability in optical fibers. By using a specifically designed time-lens system (SEAHORSE) in which aberrations are compensated, the comp ...

OPTICAL SOC AMER2021

Phase resolved characterization of nanoscale features in optical microstructures

Michail Symeonidis

In this study, we apply interferometric microscopy to study the phase, alongside the intensity, of the light field transmitted through a wide variety of samples. Additionally, we conduct those interferometric measurements at different wavelengths within th ...

EPFL2019

Sparse Lens Inversion Technique (SLIT): lens and source separability from linear inversion of the source reconstruction problem

Frédéric Courbin, Rémy Elie Joseph

Strong gravitational lensing offers a wealth of astrophysical information on the background source it affects, provided the lensed source can be reconstructed as if it was seen in the absence of lensing. In the present work, we illustrate how sparse optimi ...

EDP SCIENCES S A2019

Sky Monitoring System

Jean-Louis Scartezzini, Jérôme Henri Kämpf, Yujie Wu

In a sky monitoring system (S), comprising an image sensor (1), a wide angle lens (16), a microprocessor (3), and a memory unit (11, 18), wherein the sky monitoring system (S) is configured to take pictures of a sky scene, wherein the sky monitoring system ...

2018

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, , , , , , , ,

AAM: An Assessment Metric of Axial Chromatic Aberration

Sabine Süsstrunk, Majed El Helou, Frederike Dümbgen

Knowledge of lens specifications is important to identify the best lens for a given capture scenario and application. Lens manufacturers provide many specifications in their data sheets, and multiple initiatives for testing and comparing different lenses c ...

2018

An embedded system for quasi real-time lighting computation based on sky monitoring

Jean-Louis Scartezzini, Jérôme Henri Kämpf, Yujie Wu

Lighting simulation plays a significant role in the architectural design and evaluation of performance parameters of buildings. The general method of assuming a virtual sky in lighting simulation may lead to mismatch with the real situation, which conventi ...

2017

Synthetic diagnostic for the beam emission spectroscopy diagnostic using a full optical integration

Loïc Hausammann

The beam emission spectroscopy (BES) diagnostic is used to measure fluctuations of electron density in the edge and core of fusion plasmas, and is a key in understanding turbulence in a plasma reactor. A synthetic BES diagnostic for the turbulence simulati ...

Iop Publishing Ltd2017

Gradient-Based Correction of Chromatic Aberration in the Joint Acquisition of Color and Near-Infrared Images

Sabine Süsstrunk, Yue Lu, Zahra Sadeghipoor Kermani

Chromatic aberration distortions, such as wavelength-dependent blur caused by imperfections in photographic lenses, have long been studied in color imaging. The problem becomes more challenging to solve in the case of color and near-infrared joint acquisit ...

Spie-Int Soc Optical Engineering2015

Ultrafast All-Polymer Electrically Tunable Silicone Lenses

Herbert Shea, Samuel Rosset, Luc Maffli, Michele Ghilardi

Dielectric elastomer actuators (DEA) are smart lightweight flexible materials integrating actuation, sensing, and structural functions. The field of DEAs has been progressing rapidly, with actuation strains of over 300% reported, and many application conce ...

Wiley-Blackwell2015

Joint Acquisition of Color and Near-Infrared Images on a Single Sensor

Zahra Sadeghipoor Kermani

In the past few years, fusing NIR and color images has been explored in general computational photography and computer vision tasks, where traditionally only color images are used. The additional information provided by the differences of light and scene r ...

EPFL2015

Photonic Nanojet Array for Fast Detection of Single Nanoparticles in a Flow

Martinus Gijs, Matteo Cornaglia, Hui Yang

We detect by optical microscopy Au and fluorescent nanopartides (NPs) during their motion in water based medium, using an array of dielectric microspheres that are patterned in a microwell array template. The Microspheres act as lenses focusing the light o ...

American Chemical Society2015