Publications by Alexandre Goy | EPFL Graph Search

Imaging complex objects using learning tomography

Michaël Unser, Alexandre Goy, Demetri Psaltis, Morteza Hasani Shoreh, Joowon Lim

Optical diffraction tomography (ODT) can be described using the scattering process through an inhomogeneous media. An inherent nonlinearity exists relating the scattering medium and the scattered field due to multiple scattering. Multiple scattering is oft ...

SPIE-INT SOC OPTICAL ENGINEERING2018

Phaseless Diffraction Tomography With Regularized Beam Propagation

Michaël Unser, Alexandre Goy, Demetri Psaltis, Thanh-An Michel Pham, Ferréol Arnaud Marie Soulez, Joowon Lim, Emmanuel Emilien Louis Soubies

In recent years, researchers have obtained impressive reconstructions of the refractive index (RI) of biological objects through the combined use of advanced physics (nonlinear forward model) and regularization. Here, we propose an adaptation of these tech ...

IEEE2018

Optical Tomography Based On A Nonlinear Model That Handles Multiple Scattering

Michaël Unser, Alexandre Goy, Ulugbek Kamilov, Demetri Psaltis, Joowon Lim

Learning Tomography (LT) is a nonlinear optimization algorithm for computationally imaging three-dimensional (3D) distribution of the refractive index in semi-transparent samples. Since the energy function in LT is generally non-convex, the solution it obt ...

Ieee2017

Learning Approach to Optical Tomography

Michaël Unser, Alexandre Goy, Cédric René Jean Vonesch, Ulugbek Kamilov, Demetri Psaltis

Optical tomography has been widely investigated for biomedical imaging applications. In recent years optical tomography has been combined with digital holography and has been employed to produce high-quality images of phase objects such as cells. In this p ...

Optical Soc Amer2015

Improving the quality of filament-impaired images in Kerr media by statistical averaging

Alexandre Goy, Demetri Psaltis

In focusing Kerr media, small- scale filamentation is the major obstacle to imaging at high light intensities. In this article, we experimentally and numerically demonstrate a method based on statistical averaging to reduce the detrimental effects of filam ...

Optical Soc Amer2015

Digital confocal microscopy through a multimode fiber

Alexandre Goy, Demetri Psaltis, Ioannis Papadopoulos, Christophe Moser, Damien Claude-Marie Loterie, Salma Farahi

Acquiring high-contrast optical images deep inside biological tissues is still a challenging problem. Confocal microscopy is an important tool for biomedical imaging since it improves image quality by rejecting background signals. However, it suffers from ...

Optical Soc Amer2015

Digital confocal microscopy through a multimode fiber

Alexandre Goy, Demetri Psaltis, Ioannis Papadopoulos, Christophe Moser, Damien Claude-Marie Loterie, Salma Farahi

Confocal laser-scanning microscopy is a well-known optical imaging method where a pinhole is used in the illumination and detection pathways of a normal microscope, in order to selectively excite and detect a particular focal volume. The advantage of this ...

Spie-Int Soc Optical Engineering2015

Ablation device and method for subsurface biological tissue ablation

Alexandre Goy, Demetri Psaltis, Thomas Jean Victor Marie Lanvin, Jae-Woo Choi

The present invention relates to a subsurface laser-induced optical breakdown (LIOB) ablation system including an optical source for providing optical pulses and an optical waveguide for guiding the optical pulses to a subsurface target biological tissue s ...

2015

Digital holographic confocal microscope

Alexandre Goy, Demetri Psaltis

We demonstrate experimentally a scanning confocal microscopy technique based on digital holographic recording of the scanned spot. The data collected in this way contains all the information to produce three-dimensional images. Several methods to treat the ...

Spie-Int Soc Optical Engineering2013

Multiple contrast metrics from the measurements of a digital confocal microscope

Michaël Unser, Alexandre Goy, Demetri Psaltis

We describe various methods to process the data collected with a digital confocal microscope (DCM) in order to get more information than what we could get from a conventional confocal system. Different metrics can be extracted from the data collected with ...

Optical Soc Amer2013

Imaging and microscopy in linear and nonlinear media using digital holography

Alexandre Goy

EPFL2013

Three-Dimensional Mapping of Transparent Objects Using Kerr Nonlinearity Measurement

Alexandre Goy, Demetri Psaltis

We report a technique to produce three-dimensional maps of transparent objects using the Kerr coefficient as a contrast agent. The method is based on the spatial modifications of a probe pattern focused into the medium. (C) 2010 Optical Society of America ...

Ieee2012

Digital confocal microscope

Alexandre Goy, Demetri Psaltis

We demonstrate experimentally a scanning confocal microscopy technique based on digital holography. The method relies on digital holographic recording of the scanned spot. The data collected in this way contains all the necessary information to digitally p ...

Optical Society of America2012

Digital reverse propagation in focusing Kerr media

Alexandre Goy, Demetri Psaltis

Lenses allow the formation of clear images in homogeneous linear media. Holography is an alternative imaging method, but its use is limited to cases in which it provides an advantage, such as three-dimensional imaging. In nonlinear media, lenses no longer ...

2011