Publications associées à Optique géométrique

3D diffractive optics for linear interconnects and nonlinear processing

The optical domain presents potential avenues for enhancing both computing and communication due to its inherent properties of bandwidth, parallelism, and energy efficiency. This research focuses on harnessing 3-Dimensional (3D) diffractive optics for nove ...

EPFL2024

Modeling reflection by structured building-integrated photovoltaics

Stephen William Wasilewski

Evaluating the reflection of solar radiation by Building Integrated Photovoltaics (BIPV) with structured front-glass is challenging for two reasons. First, the resulting irregular scattering of light cannot be accounted for by simple reflection models. Sec ...

2023

Adaptive analysis-aware defeaturing

Ondine Gabrielle Chanon

Removing geometrical details from a complex domain is a classical operation in computer aided design for simulation and manufacturing. This procedure simplifies the meshing process, and it enables faster simulations with less memory requirements. However, ...

EPFL2022

Active Ferromagnetic Metasurface with Topologically Protected Spin Texture for Spectral Filters

Dirk Grundler, Haiming Yu, Jilei Chen

Electromagnetic metasurfaces modulate a material's response to electromagnetic waves by specifically arranged elements with dimensions below the wavelength. They have opened new fields of research, including flat optics and nanophotonics on a chip. Ferroma ...

2022

Optical metasurfaces: synthesis, nanofabrication, and colorful applications

Hsiang-Chu Wang

In this thesis, we mainly utilize silver to construct the meta-atoms. Although suffering from easily oxidized, its excellent lossless property throughout the visible range makes it suitable for study. When preserved properly, silver-made metasurfaces can s ...

EPFL2022

Stabilized isogeometric discretizations on trimmed and union geometries, and weak imposition of the boundary conditions for the Darcy flow

Riccardo Puppi

Modern manufacturing engineering is based on a ``design-through-analysis'' workflow. According to this paradigm, a prototype is first designed with Computer-aided-design (CAD) software and then finalized by simulating its physical behavior, which usually i ...

EPFL2022

On the Complete Radiation Pattern of a Vertical Hertzian Dipole Above a Low-Loss Ground

Krzysztof Michalski, Juan Ramon Mosig

The complete radiation field pattern of a vertical Hertzian dipole antenna on or above a lossless or low-loss dielectric half-space is studied using a rigorous Sommerfeld formalism. The reflected fields in the air above the interface and the subsurface fie ...

Ieee-Inst Electrical Electronics Engineers Inc2021

Reduction techniques for PDEs built upon Reduced Basis and Domain Decomposition Methods with applications to hemodynamics

Luca Pegolotti

This thesis focuses on the development and validation of a reduced order technique for cardiovascular simulations. The method is based on the combined use of the Reduced Basis method and a Domain Decomposition approach and can be seen as a particular imple ...

EPFL2021

Optical characterization of high numerical aperture microlenses for quality assessment and fabrication process optimization

Toralf Scharf, Wilfried Noell, Jeremy Béguelin

Accurate characterization of high numerical aperture aspheric microlenses currently is a nonstandard procedure that remains an open challenge. Here, we present and discuss a characterization method based on interferometric and point spread function measure ...

OPTICAL SOC AMER2020

Lower Hybrid Current Drive in High Aspect Ratio Tokamaks

Hoang-Trang Lam, Joan Decker, Xiaoxia Bai

A multi-machine study has been carried out to investigate the impact of a strongly bounded wave propagation domain on the Lower Hybrid current drive, a condition which occurs principally in high aspect ratio tokamaks. In this regime, the condition of kinet ...

SPRINGER2020

Highly spatially resolved mapping of the piezoelectric potentials in InGaN quantum well structures by off-axis electron holography

Victor Carle Adrien Boureau

The internal fields in 2.2nm thick InGaN quantum wells in a GaN LED structure have been investigated by using aberration-corrected off-axis electron holography with a spatial resolution of better than 1nm. To improve the spatial resolution, different types ...

2020

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

Topological Fano Resonances

Romain Christophe Rémy Fleury, Farzad Zangeneh Nejad

The Fano resonance is a widespread wave scattering phenomenon associated with a peculiar asymmetric and ultrasharp line shape, which has found applications in a large variety of prominent optical devices. While its substantial sensitivity to geometrical an ...

2019

A Compact Laser-Steering End-Effector for Transoral Robotic Surgery

Laryngeal cancer treatments, while curative, often lead to voice impairment. Minimally invasive surgical methods that facilitate greater preservation of healthy tissue have recently emerged, but they are still limited in important ways. In this work, we de ...

IEEE2019

Design and implementation of quasi-optical components for the upgrade of the TCV EC-system

Timothy Goodman, Stefano Alberti, Jean-Philippe Hogge, Laurie Porte, Matthieu Toussaint, Florian Ramseyer

The EC-system of the TCV tokamak is progressively being upgraded with the addition of two MW-class dual-frequency gyrotrons (84 and 126 GHz/2s/1MW). In order to connect the two gyrotrons to the existing low field side and top launchers, new waveguide routi ...

ELSEVIER SCIENCE SA2019

Raman imaging through multimode sapphire fiber

Demetri Psaltis, Christophe Moser, Damien Claude-Marie Loterie, Georgia Konstantinou, Sunan Deng

We report on a sapphire fiber Raman imaging probe's use for challenging applications where access is severely restricted. Small-dimension Raman probes have been developed previously for various clinical applications because they show great capability for d ...

OPTICAL SOC AMER2019

Ultrasensitive hyperspectral imaging and biodetection enabled by dielectric metasurfaces

Volkan Cevher, Hatice Altug, Filiz Yesilköy, Andreas Tittl, Yasaman Jahani, Eduardo Romero Arvelo, Mingkai Liu

Metasurfaces based on resonant subwavelength photonic structures enable novel ways of wavefront control and light focusing, underpinning a new generation of flat-optics devices. Recently emerged all-dielectric asymmetric metasurfaces, composed of arrays of ...

Nature Publishing Group2019

Matrix Fourier optics enables a compact full-Stokes polarization camera

Gabriele D'Aversa

Recent developments have enabled the practical realization of optical elements in which the polarization of light may vary spatially. We present an extension of Fourier optics-matrix Fourier optics-for understanding these devices and apply it to the design ...

American Association for the Advancement of Science2019

Design and Analysis of Binary Fan-out Gratings based on Step-Transition Perturbation Approach

Toralf Scharf, Dong Cheon Kim

Nowadays, diffractive optical elements are used for a variety of applications because of their high design flexibility, compact size, and mass productivity. At the same time, they require having high and complex optical functionalities such as a large numb ...

SPIE-INT SOC OPTICAL ENGINEERING2019

Mitsuba 2: A Retargetable Forward and Inverse Renderer

Wenzel Alban Jakob, Tizian Lucien Zeltner, Delio Aleardo Vicini, Merlin Eléazar Nimier-David

Modern rendering systems are confronted with a dauntingly large and growing set of requirements: in their pursuit of realism, physically based techniques must increasingly account for intricate properties of light, such as its spectral composition or polar ...

ASSOC COMPUTING MACHINERY2019