Publications associées à Small-size microlens characterization by multiwavelength high-resolution interference microscopy

A Cavity-Microscope for Quantum Simulations with Locally-Controllable All-to-All Interactions

This thesis presents the development, construction, and benchmark of an experimental platform that combines cold fermionic 6Li atoms with locally controllable light-matter interactions. To enable local control, a new device, the cavity-microscope, was crea ...

EPFL2024

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

Correction of spherical surface measurements by confocal microscopy

Wilfried Noell, Toralf Scharf, 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

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

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

Wilfried Noell, Toralf Scharf, 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

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

Suliana Manley, Dora Mahecic, Kyle Michael Douglass

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

DeepFocus: a Few-shot Microscope Slide Auto-Focus using a Sample Invariant CNN-based Sharpness Function

Michael Stefan Daniel Liebling, Adrian Shajkofci

Autofocus (AF) methods are extensively used in biomicroscopy, for example to acquire timelapses, where the imaged objects tend to drift out of focus. AF algorithms determine an optimal distance by which to move the sample back into the focal plane. Current ...

2020

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

Wilfried Noell, Toralf Scharf, 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

Improvements on the uniformity of large-area microlens arrays in Fused Silica

Wilfried Noell, Toralf Scharf, Jeremy Béguelin, Raoul Kirner

The uniformity of large microlens arrays in Fused Silica is governed by the production process. It comprises photolithographic patterning of a spin-coated layer of photoresist on a 200mm wafer with a molten resist reflow process and subsequent dry etching. ...

OPTICAL SOC AMER2019

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

Assessing microlens quality based on 3D irradiance measurement at the focal spot area

Wilfried Noell, Toralf Scharf, Jeremy Béguelin, Michail Symeonidis

During the fabrication process of microlenses, characterization is essential for two purposes: evaluate the optical quality of the element and provide surface information feedback for process optimization. However, no technique can fulfill these two object ...

2018

Scaling effect and its impact on wavelength-scale microlenses

Hans Peter Herzig, Myun Sik Kim, Toralf Scharf

We revisit the scaling laws in micro-optical systems to highlight new phenomena arising beyond a conventional optical regime, especially when the size of the system approaches to the operational wavelength. Our goal is to visualize the impact of the scalin ...

Spie-Int Soc Optical Engineering2017

Array imaging system for lithography

Wilfried Noell, Toralf Scharf, 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, Myun Sik Kim, Toralf Scharf

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

Hybrid PDMS/glass microfluidics for high resolution imaging and application to sub-wavelength particle trapping

Romuald Houdré, Nicolas Maxime André Descharmes, Mario Lucien Henri Tonin

We demonstrate the fabrication of a hybrid PDMS/glass microfluidic layer that can be placed on top of non-transparent samples and allows high-resolution optical microscopy through it. The layer mimics a glass coverslip to limit optical aberrations and can ...

Royal Society of Chemistry2016

Multiscale guided deblurring: Chromatic aberration correction in color and near-infrared imaging

Sabine Süsstrunk, Yue Lu, Zahra Sadeghipoor Kermani

Chromatic aberration, caused by photographic lens imperfections, results in the image of only one spectral channel being sharp, while the other channels are blurred depending on their wavelengths difference with the sharp channel. We study chromatic aberra ...

2015

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

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

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

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

Gradient-Based Correction of Chromatic Aberration in the Joint Acquisition of Color and Near-Infrared Images

Sabine Süsstrunk, Yue Lu, Zahra Sadeghipoor Kermani

Chromatic aberration distortions, such as wavelength-dependent blur caused by imperfections in photographic lenses, have long been studied in color imaging. The problem becomes more challenging to solve in the case of color and near-infrared joint acquisit ...

Spie-Int Soc Optical Engineering2015

A Practical Method for Measuring the Spatial Frequency Response of Light Field Cameras

Loïc Arnaud Baboulaz, Sabine Süsstrunk, Damien Firmenich

The spatial frequency response (SFR) is one of the most important and unbiased image quality measures of a digital camera. It evaluates to which extent a lens/sensor combination can resolve scene details. In this paper, we propose a simple and practical me ...

IEEE2014