Publications by Olivier Bernard

In situ monitoring of femtosecond laser-induced modifications in dielectrics

Over the last decades, the progress made in the generation of laser pulses shorter than a picosecond (10^-12 s) has allowed us to reach extreme optical power intensities exceeding 10^15 W cm^-2. This tremendous power has triggered an abundance of original ...

EPFL2023

Third-harmonic generation monitoring of femtosecond-laser-induced in-volume functional modifications

Christian Enz, Yves Bellouard, Olivier Bernard, Assim Boukhayma, Andrea Kraxner

During the last two decades, ultrafast in-volume laser-based processing of transparent materials has emerged as a key 3D-printing method for manufacturing a variety of complex integrated photonic devices and micro-parts. Yet, identifying suitable laser pro ...

2023

High-efficiency non-ablative UV laser nano-scale processing of fused silica by stable filamentation

Yves Bellouard, Olivier Bernard, Benedikt Hermann, Luca Muscarella

Over the last decades, three-dimensional micro-manufacturing of fused silica via near-infrared ultrafast laser exposure combined with an etching step has become an established technique for producing complex three-dimensional components. Here, we explore t ...

2023

On the use of a digital twin to enhance femtosecond laser inscription of arbitrary phase patterns

Yves Bellouard, Olivier Bernard

2021

A sparse reconstruction framework for Fourier-based plane wave imaging

Jean-Philippe Thiran, Yves Wiaux, Olivier Bernard, Adrien Georges Jean Besson, Rafael Eduardo Carrillo Rangel

Ultrafast imaging based on plane-wave (PW) insonification is an active area of research due to its capability of reaching high frame rates. Among PW imaging methods, Fourier-based approaches have demonstrated to be competitive compared to traditional delay ...

Ieee-Inst Electrical Electronics Engineers Inc2016

Sparse regularization methods in ultrafast ultrasound imaging

Jean-Philippe Thiran, Yves Wiaux, Olivier Bernard, Adrien Georges Jean Besson, Rafael Eduardo Carrillo Rangel

Ultrafast ultrasound (US) imaging based on plane wave (PW) insonification is a widely used modality nowadays. Two main types of approaches have been proposed for image reconstruction either based on classical delay-and-sum (DAS) or on Fourier reconstructio ...

Ieee2016

A compressed beamforming framework for ultrafast ultrasound imaging

Jean-Philippe Thiran, Yves Wiaux, Olivier Bernard, Dimitris Perdios, Adrien Georges Jean Besson, Rafael Eduardo Carrillo Rangel, Marcel Arditi

Classical beamforming methods, based on Delay- And-Sum (DAS) require an extensive number of samples and delay calculations to obtain high-quality images. Compressed Beamforming (CB) proposes an alternative to DAS, based on compressed sensing, which aims at ...

Ieee2016

A sparse regularization approach for ultrafast ultrasound imaging

Jean-Philippe Thiran, Yves Wiaux, Olivier Bernard, Adrien Georges Jean Besson, Rafael Eduardo Carrillo Rangel

Ultrafast imaging based on plane-wave (PW) in- sonification is an active area of research due to its capability of reaching high frame rates. Several approaches have been proposed either based on either of Fourier-domain reconstruction or on delay-and-sum ...

IEEE2015

Extension of ultrasound Fourier slice Imaging theory to sectorial acquisition

Jean-Philippe Thiran, Olivier Bernard, Adrien Georges Jean Besson, Rafael Eduardo Carrillo Rangel

Ultrasound image reconstruction from the echoes received by an ultrasound probe after the transmission of diverging waves is an active area of research because of its capacity to insonify at ultra-high frame rate with large regions of interest using small ...

2015

Variational B-Spline Level-Set: A Linear Filtering Approach for Fast Deformable Model Evolution

Philippe Thévenaz, Michaël Unser, Olivier Bernard

In the field of image segmentation, most level-set-based active-contour approaches take advantage of a discrete representation of the associated implicit function. We present in this paper a different formulation where the implicit function is modeled as a ...

IEEE2009

Probabilistic observers for a class of uncertain biological processes

Benoît Chachuat, Olivier Bernard

In this paper, probabilistic observers are considered for a class of continuous biological processes described by mass-balance-based models. It is assumed that the probability density functions (PDFs) of the uncertain parameters and inputs of the model, as ...

2006

Can we assess the model complexity for a bioprocess: theory and example of the anaerobic digestion process

Benoît Chachuat, Olivier Bernard

In this paper we propose a methodology to determine the structure of the pseudo-stoichiometric coefficient matrix K in a mass balance based model, i.e. the maximal number of biomasses that must be taken into account to reproduce an available data set. It c ...

2006

Assessing Model Complexity from Anaerobic Digestion Data: When is Model AM1 Required?

Benoît Chachuat, Olivier Bernard

The anaerobic digestion ecosystem is complex, involving a broad variety of substrates and up to 140 bacterial species. This paper applies a methodology that determines the least number of macroscopic bioreactions to be taken into account in order to explai ...

2005

An integrated system to remote monitor and control anaerobic wastewater treatment plants through the internet

Gabriel Ruiz, Benoît Chachuat, Olivier Bernard, Pierre Lemaire, Andrea Franco

The TELEMAC project brings new methodologies from the Information and Science Technologies field to the world of water treatment. TELEMAC offers an advanced remote management system which adapts to most of the anaerobic wastewater treatment plants that do ...

2005

Design and Practical Use of Probabilistic Observers for Mass-Balance-Based Bioprocess Models

Benoît Chachuat, Olivier Bernard

In this paper, the design of probabilistic observers for mass-balance based bio- process models is investigated. It is assumed that the probability density function of every uncertain parameter, input and/or initial state is known a priori. Then, the proba ...

2004

Design of Probabilistic Observers for Mass-Balance-Based Bioprocess Models

Benoît Chachuat, Olivier Bernard

In this paper, the design of probabilistic observers for mass-balance based bioprocess models is investigated. It is assumed that the probability density of every uncertain parameter, input and/or initial state is known a priori. Then, the probability dens ...

2004

A Two-Step Procedure for Estimating the Parameters in Mass-Balance-Based Bioprocess Models

Benoît Chachuat, Olivier Bernard

In this paper, we consider a two-step procedure for estimating the parameters in mass-balance based bioprocess models. In the first step, the values or combinations of the yield coefficients are calculated from mass-balance considerations without formulati ...

2004

Comportement à long terme des éléments de structure formés de bétons d'âges différents

Olivier Bernard

EPFL2000