Publications associées à Axe optique

Phase calibration of a basic bright-field microscope for 3D metrology of transparent samples at the nanoscale

Martinus Gijs, Daniel Migliozzi, Bingying Zhao

Optical retrieval of the structure of transparent objects at the nano-scale requires adapted methods capable of probing their interaction with suitable light. Scattering events, for instance, depend on the content and the arrangement of the medium encounte ...

SPIE-INT SOC OPTICAL ENGINEERING2021

Learning approaches to high-fidelity optical diffraction tomography

Joowon Lim

Optical diffraction tomography (ODT) provides us 3D refractive index (RI) distributions of transparent samples. Since RI values differ across different materials, they serve as endogenous contrasts. It, therefore, enables us to image without pre-processing ...

EPFL2020

Leveraging wafer-level manufacturing process limitations to increase large scale fused silica microlens array uniformity

Toralf Scharf, Wilfried Noell, Raoul Kirner, Jeremy Béguelin

The wafer-level production of Fused Silica microlens arrays is limited by systematic process non-uniformities. The common molten resist-reflow process with subsequent dry-etching allows for manufacturing of microlens arrays on 200 mm wafers. A thorough pro ...

SPIE-INT SOC OPTICAL ENGINEERING2019

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

Multi-material micro-electromechanical fibers with bendable functional domains

Fabien Sorin, Wei Yan, Alexis Gérald Page, Yunpeng Qu, Marco Volpi

The integration of increasingly complex functionalities within thermally drawn multi-material fibers is heralding a novel path towards advanced soft electronics and smart fabrics. Fibers capable of electronic, optoelectronic, piezoelectric or energy harves ...

2017

Observation device with optical compensation

Philippe Renaud, Yann Barrandon, David Vincent Bonzon, David Forchelet, Steve Béguin

The invention concerns an observation device such as cell culture wells comprising an optical element such as a lens or a filter, or even combinations thereof, for compensating an optical effect induced on a sample contained in the observation device and i ...

2016

Landmark Detection for Fusion of Fundus and MRI Toward a Patient-Specific Multimodal Eye Model

Meritxell Bach Cuadra, Carlos Ciller

Ophthalmologists typically acquire different image modalities to diagnose eye pathologies. They comprise, e.g., Fundus photography, optical coherence tomography, computed tomography, and magnetic resonance imaging (MRI). Yet, these images are often complem ...

Ieee-Inst Electrical Electronics Engineers Inc2015

Upconversion Particle as a Local Luminescent Brownian Probe: A Photonic Force Microscopy Study

László Forró, Andrzej Sienkiewicz, Flavio Maurizio Mor, Sylvia Jeney

Near-infrared (NIR) light sensitive lanthanide-doped NaYF4 upconversion particles (UCPs) are gaining increasing attention as local probes in biomedical applications. Here, we implemented a photonic force microscope (PFM) to manipulate and study the optical ...

Amer Chemical Soc2014

Experimental and theoretical investigation on the misalignment tolerance of a micron-sized solid immersion lens tolerance of a micron-sized solid immersion lens

Hans Peter Herzig, Toralf Scharf, Myun Sik Kim

We report an experimental and theoretical study on the alignment error tolerance of a 2 µm-size solid immersion lens (SIL) illuminated by different types of focused spots. Tightly confined focal spots are of great interest for improving the performance of ...

Iop Publishing Ltd2013

Multiple Phase Anomalies in Bessel Beam

Hans Peter Herzig, Toralf Scharf, Myun Sik Kim

The non-diverging feature of the Bessel-kind beam leads to multiple phase anomalies along the optical axis in contrary to the focused Gaussian beam. Here, we analyze the phase distributions using in a longitudinal-differential phase mode of a high-resoluti ...

2013

Phase anomalies in Talbot light carpets of selfimages

Hans Peter Herzig, Toralf Scharf, Myun Sik Kim

An interesting feature of light fields is a phase anomaly, which occurs on the optical axis when light is converging as in a focal spot. Since in Talbot images the light is periodically confined in both transverse and axial directions, it remains an open q ...

Optical Society of America2013

Physics of Polariton Condensates in GaN-based Planar Microcavities

Jacques Levrat

Since its prediction in 1996 by Imamoğlu and coworkers, the use of a non-equilibrium polariton condensate to produce an intense coherent light source referred to as a polariton laser has attracted a lot of interest in the whole physics community as it ...

EPFL2012

On the Characteristics of Highly Confined Light Fields : A High-Resolution Interference Microscopy Study

Myun Sik Kim

The Investigation of highly confined light fields created by different mechanisms, such as refraction, diffraction, and scattering, are the main subject of this thesis. We distinguish a specific scattering phenomenon of dielectric microspheres from general ...

EPFL2011

Extended Focus Optical Coherence Microscopy : Theory and Application

Martin Villiger

Optical coherence tomography (OCT) is an interferometric imaging technique that can provide depth resolved cross-sectional views of biological tissue. OCT employs light with low temporal and yet high spatial coherence. The sample is illuminated point by po ...

EPFL2010

Cellular dynamics explored with digital holographic microscopy

Benjamin Rappaz

Obtaining high resolution 3D quantitative images is critical for elucidating the relationship between cell dynamics and physiological or pathological processes. However the feasibility of such cellular dynamic studies is limited by the resolution of the 3D ...

EPFL2008

Shot noise, refractive index tomography and aberrations estimation in digital holographic microscopy

Florian Charrière

The present thesis develops some specific aspects of digital holographic microscopy (DHM), namely the effect of shot noise on the phase image accuracy, the use of DHM in micro-tomography and in aberrations evaluation of a microscope objective (MO). DHM is ...

EPFL2007

Nanometer focusing properties of Fresnel zone plates described by dynamical diffraction theory

Christian David

The x-ray focusing properties of linear Fresnel zone plates have been derived by solving the Helmholtz equation for the field propagating through the zones. We consider the imaging of a point object into the first diffraction order of a volume zone plate h ...

2006

Purely numerical compensation for microscope objective phase curvature in digital holographic microscopy: influence of digital phase mask position

Christian Depeursinge, Tristan Colomb, Etienne Cuche, Frédéric Montfort, Pierre Marquet, Florian Charrière

Introducing a microscope objective in an interferometric setup induces a phase curvature on the resulting wavefront. In digital holography, the compensation of this curvature is often done by introducing an identical curvature in the reference arm and the ...

2006

Étude expérimentale des propriétés optiques des cristaux photoniques bidimensionnels et de leur accordabillité

Barbara Wild

Photonic crystals are periodic dielectric structures, where the periodicity varies in one, two or three dimensions. Analogous to the periodic potential of electrons in semiconductors, the periodic variation of the dielectric constant influences the electro ...

EPFL2006

Measurement and interpretation of the 3D amplitude point spread function of lenses and microscope objectives

Mihaela Marian

The intensity point spread function (IPSF) is most often used to characterize optical imaging systems. For some imaging applications such as digital holographic microscopy the 3D amplitude point spread function (APSF) more completely describes an optical s ...

EPFL2005