Publications associées à Microlentille

Towards learning-based denoising of light fields

Touradj Ebrahimi, Michela Testolina, Tomás Soares De Carvalho Feith

In recent years, new emerging immersive imaging modalities, e.g. light fields, have been receiving growing attention, becoming increasingly widespread over the years. Light fields are often captured through multi-camera arrays or plenoptic cameras, with th ...

2023

Strong and micro lensing in distant quasars

Eric Gérard Guy Paic

Most large galaxies contain Super Massive Black Holes at their centers, drawing matter nearby to form swirling accretion disks emitting electromagnetic radiation. These are Active Galactic Nuclei. The brightest quasars are the most luminous Universe object ...

EPFL2023

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

On the assessment of aspheric refractive microlenses

Jeremy Béguelin

Refractive microlenses and microlens arrays are key components for many applications such as optical data communication, laser and medical devices, or cameras. In particular, refractive micro-optics enables the miniaturization of high-tech systems but also ...

EPFL2020

Koehler integrator device and application thereof in a multi-focal confocal microscope

Suliana Manley, Kyle Michael Douglass, Dora Mahecic

A Koehler integrator device (10) comprises a collimating lens (11) being arranged for collimating a light field created by an incoherent or partially coherent light source, a pair of planar first and second micro-lens arrays (12, 13) being arranged for rel ...

2020

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

Correction of spherical surface measurements by confocal microscopy

Toralf Scharf, Wilfried Noell, Jeremy Béguelin

Refractive microlenses are nowadays widely used in optical systems. Characterizing their surface is essential to ensure their quality and to optimize their fabrication process. This is realized by optical surface profilers thanks to their vertical resoluti ...

2020

Plano-concave mini-lens array for plenoptic imaging applications

Toralf Scharf, Alessandro Grosso

An array of plano-concave mini-lenses is designed to realize a particular version of Light Field camera known as Plenoptic Camera 1.2. The Delano diagram related to the on-axis optical channel of such a camera is computed to show its retro-focus behavior a ...

IEEE2019

Specification of aspherical surfaces used as refractive elements in micro-optical systems

Toralf Scharf, Wilfried Noell, Jeremy Béguelin

The optical performance of refractive plano-convex microlenses is mainly related to the quality of their (a)spherical surface. An efficient tolerancing of this surface is a key step towards the manufacturing of high quality microlenses. However, we demonst ...

SPIE-INT SOC OPTICAL ENGINEERING2019

Phase resolved characterization of nanoscale features in optical microstructures

Michail Symeonidis

In this study, we apply interferometric microscopy to study the phase, alongside the intensity, of the light field transmitted through a wide variety of samples. Additionally, we conduct those interferometric measurements at different wavelengths within th ...

EPFL2019

Turning a normal microscope into a super-resolution instrument using a scanning microlens array

Martinus Gijs, Gergely Huszka

We report dielectric microsphere array-based optical super-resolution microscopy. A dielectric microsphere that is placed on a sample is known to generate a virtual image with resolution better than the optical diffraction limit. However, a limitation of s ...

Nature Research2018

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

Binary zero-order diffractive and anti-reflective optical elements in silicon for the mid-infrared

Hans Peter Herzig, Grégoire Maxime Smolik

We propose a novel method for the design of binary 2-level diffractive optical elements that provide an efficient diffractive function while reducing the reflectivity of a high-index interface. The structure can be fabricated with a single patterning step ...

Optical Society of America2017

Array imaging system for lithography

Toralf Scharf, Wilfried Noell, Raoul Kirner

We present an integrated array imaging system based on a stack of microlens arrays. The microlens arrays are manufactured by melting resist and reactive ion etching (RIE) technology on 8'' wafers (fused silica) and mounted by wafer-level packaging (WLP)(1) ...

Spie-Int Soc Optical Engineering2016

Unconventional Optical Responses of Wavelength-scale Microlenses: beyond Refraction Limit

Hans Peter Herzig, Toralf Scharf, Myun Sik Kim

Miniaturized optical systems show often unconventional responses compare to larger systems of the same design. We investigate such new phenomena using microlenses, and demonstrate characteristics beyond the refraction limit of the micro-optical systems. ...

Ieee2016

System for optical detection and imaging of sub-diffraction-limited nano-objects

Martinus Gijs, Matteo Cornaglia, Hui Yang

Nano-objects (8) with feature size smaller than the classical Abbe's diffraction limit can be optically detected via a microlens (4) array configured in a miniaturized microfluidic device. A hydrophilic microwell (3) array in a hydrophobic layer (2) is fir ...

2016

Excitation of resonant plasmonic cavities by integrated waveguides for sensing applications

Gaël David Osowiecki

Optical sensors represent a large growing market which is nowadays focusing onto advancement in mobile technology. Innovations in the field of optical sensors are mostly driven by the technological advancements in the domain of micro & nanofabrication. One ...

EPFL2016

Refraction limit of miniaturized optical systems: a ball-lens example

Hans Peter Herzig, Roland Andreas Bitterli, Toralf Scharf, Wilfried Noell, Myun Sik Kim

We study experimentally and theoretically the electromagnetic field in amplitude and phase behind ball-lenses across a wide range of diameters, ranging from a millimeter scale down to a micrometer. Based on the observation, we study the transition between ...

Optical Society of America2016

Organic-inorganic-hybrid-polymer microlens arrays with tailored optical characteristics and multi-focal properties

Jürgen Brugger, Victor Javier Cadarso Busto, Loïc Jacot-Descombes

Plano-convex microlens arrays of organic-inorganic polymers with tailored optical properties are presented. The fine-tuning of each microlens within an array is achieved by confining inkjet printed drops of the polymeric ink onto pre-patterned substrates. ...

Optical Society of America2015

On the Accuracy of Point Localisation in a Circular Camera-Array

Martin Vetterli, Adam James Scholefield, Alireza Ghasemi

Although many advances have been made in light-field and camera-array image processing, there is still a lack of thorough analysis of the localisation accuracy of different multi-camera systems. By considering the problem from a frame-quantisation perspect ...

2015