Publications associées à Lunette astronomique

Performance of the MALTA telescope

Edoardo Charbon, Francesco Piro, Abhishek Sharma

MALTA is part of the Depleted Monolithic Active Pixel sensors designed in Tower 180 nm CMOS imaging technology. A custom telescope with six MALTA planes has been developed for test beam campaigns at SPS, CERN, with the ability to host several devices under ...

SPRINGER2023

Multi-object spectroscopic operations with the Sloan Digital Sky Survey V

Ricardo Jorge Araùjo Pereira, Luzius Gregor Kronig, Loïc Grossen

The Sloan Digital Sky Survey V (SDSS-V) is an all-sky spectroscopic survey of more than 6 million objects, designed to decode the history of the Milky Way, reveal the inner workings of stars, investigate the origin of solar systems, and track the growth of ...

SPIE-INT SOC OPTICAL ENGINEERING2020

Near-field phase profile and far-field contrast modulation for micro-lens arrays at the refraction limit

Toralf Scharf, Maryam Yousefi, Daniel Necesal

We investigate the far-field pattern generation for a micro-lens array (MLA) illuminated under different conditions. Plane wave and Gaussian beam illumination are considered for an MLA with a small diameter of 27 microns and 30 microns period. At these dim ...

2020

COSMOGRAIL: XIX. Time delays in 18 strongly lensed quasars from 15 years of optical monitoring star

Frédéric Courbin, Georges Meylan, Malte Tewes, Eric Gérard Guy Paic, Vivien François Bonvin, Hung-Hsu Chan, Olga Tihhonova, Martin Raoul Robert Millon, Aymeric Alexandre Galan, Rémy Elie Joseph, Cameron Alexander Campbell Lemon

We present the results of 15 years of monitoring lensed quasars, which was conducted by the COSMOGRAIL programme at the Leonhard Euler 1.2 m Swiss Telescope. The decade-long light curves of 23 lensed systems are presented for the first time. We complement ...

EDP SCIENCES S A2020

Precision Positioning of Microrobots for Multi-Object Spectrographs

Luzius Gregor Kronig

How does one study the evolution of the Milky Way, or the expansion of the Universe, or explore the mysteries of Dark energy? To investigate these complex topics, astronomers require data, and a great deal of it, in the form of the spectra of stars, galaxi ...

EPFL2020

Specification of aspherical surfaces used as refractive elements in micro-optical systems

Toralf Scharf, Wilfried Noell, Jeremy Béguelin

The optical performance of refractive plano-convex microlenses is mainly related to the quality of their (a)spherical surface. An efficient tolerancing of this surface is a key step towards the manufacturing of high quality microlenses. However, we demonst ...

SPIE-INT SOC OPTICAL ENGINEERING2019

Plano-concave mini-lens array for plenoptic imaging applications

Toralf Scharf, Alessandro Grosso

An array of plano-concave mini-lenses is designed to realize a particular version of Light Field camera known as Plenoptic Camera 1.2. The Delano diagram related to the on-axis optical channel of such a camera is computed to show its retro-focus behavior a ...

IEEE2019

Low-dimensional data embedding for scalable astronomical imaging in the SKA telescope era

Vijay Kartik

Astronomy is one of the oldest sciences known to humanity. We have been studying celestial objects for millennia, and continue to peer deeper into space in our thirst for knowledge about our origins and the universe that surrounds us. Radio astronomy -- ob ...

EPFL2018

Aberrations analysis of a Focused Plenoptic Camera

Toralf Scharf, Alessandro Grosso

A Focused Plenoptic Camera in Galilean configuration is studied and its aberrations behavior is interpreted with the Nodal Aberration Theory (NAT). Sequential ray tracing is applied to individual optical channels constituted by the camera objective and ind ...

2018

Design of a refractive surface

Mark Pauly, Yuliy Gennadievich Schwartzburg

Method of designing a refractive surface, comprising providing a refractive object having a refractive surface with an initial geometry, determining a refraction of incident illumination through the refractive surface with the initial geometry to create a ...

2017

Unconventional Optical Responses of Wavelength-scale Microlenses: beyond Refraction Limit

Hans Peter Herzig, Toralf Scharf, Myun Sik Kim

Miniaturized optical systems show often unconventional responses compare to larger systems of the same design. We investigate such new phenomena using microlenses, and demonstrate characteristics beyond the refraction limit of the micro-optical systems. ...

Ieee2016

Back-Propagating the Light of Field Stars to Probe Telescope Mirrors Aberrations

Michaël Unser, Frédéric Courbin, Ferréol Arnaud Marie Soulez

We propose a wavefront-based method to estimate the PSF over the whole field of view. This method estimate the aberrations of all the mirrors of the telescope using only field stars. In this proof of concept paper, we described the method and present some ...

SPIE2016

Refraction limit of miniaturized optical systems: a ball-lens example

Hans Peter Herzig, Roland Andreas Bitterli, Toralf Scharf, Wilfried Noell, Myun Sik Kim

We study experimentally and theoretically the electromagnetic field in amplitude and phase behind ball-lenses across a wide range of diameters, ranging from a millimeter scale down to a micrometer. Based on the observation, we study the transition between ...

Optical Society of America2016

Color reproduction, pattern hiding and image alternations with halftone prints on metal

Roger Hersch, Petar Pjanic

We propose new methods for creating color or achromatic images that are printed with classical cyan, magenta, yellow and a white diffusing ink on a metallic substrate. We optimize the surface coverages of the cyan, magenta, yellow and white inks in order t ...

2016

Transition of optical regime in miniaturized optical systems: light interactions beyond the refraction limit

Hans Peter Herzig, Toralf Scharf, Myun Sik Kim

We investigate the transition of optical regimes of miniaturized optical systems using two canonical examples, where the refraction of light limits the system performance. A ball-lens and a solid immersion lens (SIL) are considered, whose refractive respon ...

Spie-Int Soc Optical Engineering2016

Short- and long-range polar order contributions to the Ferroelectric phase of Ca2+ doped SrTiO3

Alexander Tagantsev

Short- and long-range impurity-induced polar ordering in Sr1-xCaxTiO3 (x = 0.014) single crystals was investigated and discussed on the basis of light refraction, morphic birefringence and temperature-dependent dielectric hysteresis loop measurements. Anew ...

Iop Publishing Ltd2016

Super-Resolution Imaging of a Dielectric Microsphere Is Governed by the Waist of Its Photonic Nanojet

Martinus Gijs, Raphaël Etienne Jean Trouillon, Hui Yang, Gergely Huszka

Dielectric microspheres with appropriate refractive index can image objects with super-resolution, that is, with a precision well beyond the classical diffraction limit. A microsphere is also known to generate upon illumination a photonic nanojet, which is ...

American Chemical Society2016

The major upgrade of the MAGIC telescopes, Part II: A performance study using observations of the Crab Nebula

MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a series of upgrades, involving the exchange of the MAGIC-I camera and its trigger system, as well a ...

Elsevier Science Bv2016

On Micro Optical Elements for Efficient Light Diffusion

Roland Andreas Bitterli

Efficient light management is one of the key issues in modern energy conversion systems, be it to collect optical power or to redistribute light generated by high power light emitters. This thesis touches mainly on the subject of efficient light redistribu ...

EPFL2013

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses XIV. Time delay of the doubly lensed quasar SDSS J1001+5027

Frédéric Courbin, Georges Meylan, Malte Tewes

This paper presents optical R-band light curves and the time delay of the doubly imaged gravitationally lensed quasar SDSS J1001+5027 at a redshift of 1.838. We have observed this target for more than six years, between March 2005 and July 2011, using the ...

Edp Sciences S A2013