Publications associées à Vergence

Transfer learning application of self-supervised learning in ARPES

There is a growing recognition that electronic band structure is a local property of materials and devices, and there is steep growth in capabilities to collect the relevant data. New photon sources, from small-laboratory-based lasers to free electron lase ...

IOP Publishing Ltd2023

LensWatch. I. Resolved HST Observations and Constraints on the Strongly Lensed Type Ia Supernova 2022qmx ("SN Zwicky")

Frédéric Courbin, Adriano Agnello

Supernovae (SNe) that have been multiply imaged by gravitational lensing are rare and powerful probes for cosmology. Each detection is an opportunity to develop the critical tools and methodologies needed as the sample of lensed SNe increases by orders of ...

IOP Publishing Ltd2023

Structured light generation by refractive-diffractive micro optical array illuminators

Maryam Yousefi

Structured light generation having broad applications in different optical fields, is the topic of this thesis. Our structured light generation strategy is based on applying periodic microoptical elements at the refraction-diffraction limit, under a focuse ...

EPFL2021

Structured light engineering using a photonic nanojet

Toralf Scharf, Maryam Yousefi, Daniel Necesal

In this Letter, we present the photonic nanojet as a phenomenon in a structured light generator system that is implemented to modify the source focal spot size and emission angle. The optical system comprises a microlens array that is illuminated by a focu ...

OPTICAL SOC AMER2021

Analysis of a Novel Toroidal Configuration for Hadron Therapy Gantries

Enrico Felcini

Hadron therapy refers to a medical treatment that uses hadron beams (i.e. protons and ions) to deliver localized energy that suppresses cancerous cells, sparing the neighbouring healthy tissues from unwanted radiation. The major technical components of a h ...

EPFL2021

Large field of view multi-camera endoscopic apparatus with omni-directional illumination

Yusuf Leblebici, Ömer Cogal

A multi-camera hemispherical very wide field of view imaging apparatus with omnidirectional illumination capability comprises a cylindrical body (4, 4.a, 4.b), a hemispherical mechanical frame (2) arranged on one end of the cylindrical body (4, 4.a, 4.b), ...

2020

Single crystal diamond gain mirrors for high performance vertical external cavity surface emitting lasers

Niels Quack, Grigore Suruceanu, Gergely Huszka, Alexandru Mereuta, Andrei Caliman, Pascal Gallo, Mehdi Naamoun

We report on the design, fabrication and optical performance of gain mirrors in single crystal diamond substrates for vertical external cavity surface emitting lasers (VECSELs). VECSELs have gained attention recently due to their potential for high emissio ...

2020

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

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

Large Field of View Multi-Camera Endoscopic Apparatus with Omni-Directional Illumination

Yusuf Leblebici, Ömer Cogal

A multi-camera hemispherical very wide field of view imaging apparatus with omnidirectional illumination capability comprises a cylindrical body (4, 4.a, 4.b), a hemispherical mechanical frame (2) arranged on one end of the cylindrical body (4, 4.a, 4.b), ...

2017

Aberrations of the point spread function of a multimode fiber due to partial mode excitation

Adrien Charles-François Raymond Descloux

We investigate the point spread function of a multimode fiber. The distortion of the focal spot created on the fiber output facet is studied for a variety of the parameters. We develop a theoretical model of wavefront shaping through a multimode fiber and ...

Optical Society of America2016

Transition of optical regime in miniaturized optical systems: light interactions beyond the refraction limit

Hans Peter Herzig, Toralf Scharf, Myun Sik Kim

We investigate the transition of optical regimes of miniaturized optical systems using two canonical examples, where the refraction of light limits the system performance. A ball-lens and a solid immersion lens (SIL) are considered, whose refractive respon ...

Spie-Int Soc Optical Engineering2016

Design of periodic nano- and macro-scale textures for high-performance thin-film multi-junction solar cells

Christophe Ballif, Franz-Josef Haug, Etienne Antoine Julien Moulin

Surface textures in thin-film silicon multi-junction solar cells play an important role in gaining the photocurrent of the devices. In this paper, a design of the textures is carried out for the case of amorphous silicon/micro-crystalline silicon (a-Si:H/m ...

Iop Publishing Ltd2016

Two-photon fluorescence imaging through multicore fiber with digital phase conjugation

Demetri Psaltis, Christophe Moser, Nicolino Stasio, Donald Benjaman Conkey

We present near diffraction limited two photon fluorescence (TPF) imaging through a lensless, multi-core fiber (MCF) endoscope utilizing digital phase conjugation. The ultra-small size of MCFs make them desirable tools for imaging deep into the body. TPF i ...

Spie-Int Soc Optical Engineering2016

Joint Acquisition of Color and Near-Infrared Images on a Single Sensor

Zahra Sadeghipoor Kermani

In the past few years, fusing NIR and color images has been explored in general computational photography and computer vision tasks, where traditionally only color images are used. The additional information provided by the differences of light and scene r ...

EPFL2015

Grazing angle X-ray fluorescence from periodic structures on silicon and silica surfaces

Andreea Veronica Savu, Wei Cao

Various 3-dimensional nano-scaled periodic structures with different configurations and periods deposited on the surface of silicon and silica substrates were investigated by means of the grazing incidence and grazing emission X-ray fluorescence techniques ...

Pergamon-Elsevier Science Ltd2014

Generation of 0.9-mJ THz pulses in DSTMS pumped by a Cr:Mg2SiO4 laser

Christoph Peter Hauri

We report on high-field terahertz transients with 0.9-mJ pulse energy produced in a 400 mm(2) partitioned organic crystal by optical rectification of a 30-mJ laser pulse centered at 1.25 mu m wavelength. The phase-locked single-cycle terahertz pulses cover ...

Optical Society of America2014

A microfluidic flow-cell for the study of the ultrafast dynamics of biological systems

Majed Chergui, Adrien Alexis Paul Chauvet

The study of biochemical dynamics by ultrafast spectroscopic methods is often restricted by the limited amount of liquid sample available, while the high repetition rate of light sources can induce photodamage. In order to overcome these limitations, we de ...

American Institute of Physics2014

Stationary solar concentrator delivering beyond the étendue law with homogeneous illumination

Marilyne Andersen, Boris Clément Karamata

We describe a concept for a novel stationary solar concentrator that relies on a new self-adaptive optical valve, non-imaging optics and the integrating sphere principle. Our analytical model reveals that this unique combination theoretically allows reachi ...

2014

On Micro Optical Elements for Efficient Light Diffusion

Roland Andreas Bitterli

Efficient light management is one of the key issues in modern energy conversion systems, be it to collect optical power or to redistribute light generated by high power light emitters. This thesis touches mainly on the subject of efficient light redistribu ...

EPFL2013