Concept

Optique

Publications associées (532)

Study of the beam path distortion profiles generated by a two-axis tilt single-mirror laser scanner

René Salathé, Thomas Sidler, Moustapha Hafez

Beam distortion profiles are studied for scanning devices that have a single mirror with two rotational degrees of freedom (DOF), also named tip/tilt scanners. The case of a fast steering scanner used for high power material processing applications is stud ...

2003

Non-Linear Fresnelet Approximation for Interference Term Suppression in Digital Holography

Michaël Unser, Thierry Blu

We present a zero-order and twin image elimination algorithm for digital Fresnel holograms that were acquired in an off-axis geometry. These interference terms arise when the digital hologram is reconstructed and corrupt the result. Our algorithm is based ...

SPIE2003

Characterization of the response of fibre Bragg grating sensors subjected to a two-dimensional strain field

René Salathé, John Botsis, Hans Georg Limberger, Federico Bosia, Philippe Giaccari

In this paper, the behaviour of fibre Bragg grating sensors subjected to transversal as well as axial strains is characterized, both in the case of low-birefringent and polarization-maintaining single-mode optical fibres. Two configurations are considered. ...

2003

Moire patterns between aperiodic layers: quantitative analysis and synthesis

Isaac Amidror

Moire effects that occur in the superposition of aperiodic layers such as random dot screens are known as Glass patterns. Unlike classical moiré effects between periodic layers, which are periodically repeated throughout the superposition, a Glass p ...

Opt. Soc. America2003

Micro-optical fer switch for a large number of inetrconnects: optical design considerations and experimental realizations using microlens arrays

Hans Peter Herzig, René Dändliker

The authors investigate a 1 × N free-space microoptical fiber switch for a large number of interconnects. The system to be studied is a reflective 4 f optical system. Alignment tolerances and coupling efficiency are investigated and the benefit brought by ...

2002

Coherent optical information systems

Demetri Psaltis

Coherent optical beams are used to communicate, store, and process information in a growing number of applications. The availability of coherent laser sources is of critical importance for the realization of such optical information systems. An incoherent ...

2002

Quantum kinetics of parametric polariton scattering in microcavities

Benoît Marie Joseph Deveaud, Stefan Kundermann, Cristiano Ciuti, Michele Saba

An investigation of the parametric amplification and its coherent control in a semiconductor micro-cavity is presented. The time and angle resolved pump and probe experiments show that several ps after pumping parametric scattering is still phase coherent. ...

2002

Etude des phénomènes d'écran et de polarisation dans un plasma quantique par la méthode des graphes de Mayer

This thesis is devoted to the study of screening and polarisation effects in a quantum plasma of electrons and protons, when the system is close to a dilute gas of hydrogen atoms. This atomic phase is obtained by considering a coupled low-density and low-t ...

EPFL2002

Light propagation through alignment-patterned liquid crystal gratings

Toralf Scharf

We analysed the light propagation through alignment-patterned liquid crystal films where the alignment is planar and homeotropic for different domains, respectively. Using elastic theory the nematic director field can be analytically calculated with the me ...

2002

Dielectric constants of Zr silicates: A first-principles study

Alfredo Pasquarello, Angelo Bongiorno

Using density-functional theory, we compute the optical and static dielectric constants for a set of Zr silicates modeled by various SiO2 crystals, with Zr atoms substitutional to Si, and by an amorphous structure. We then derive a microscopic scheme that ...

2002

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