Publications related to Optical engineering

Intraocular Lens Refractive Index and Its Impact on External Surface Reflections

PURPOSE: To determine and compare the origin of the external surface reflections produced by commonly used intraocular lenses (IOLs). ...

SLACK INC2021

High-Resolution Multi-Spectral Imaging With Diffractive Lenses and Learned Reconstruction

Oguzhan Fatih Kar, Can Deniz Bezek

Spectral imaging is a fundamental diagnostic technique with widespread application. Conventional spectral imaging approaches have intrinsic limitations on spatial and spectral resolutions due to the physical components they rely on. To overcome these physi ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2021

Lens aberration compensation in interference microscopy

Yves Bellouard, Jakub Drs

Emergence of products that feature functional surfaces with complex geometries, such as freeform optics in consumer electronics and augmented reality and virtual reality, requires high-accuracy non-contact surface measurement. However, large discrepancies ...

2020

Precise and accurate image-based measurements of optical material properties

Marjan Shahpaski

The appearance of objects is governed by how they reflect, transmit and absorb the light they receive. That, in turn, depends on the material's internal structure, surface structure, and viewing and illumination directions. Changes in those characteristics ...

EPFL2020

Time-lapse high-resolution microscopy to study the morphogenesis of microorganisms

Mélanie Thérèse Marie Hannebelle

Mycobacterium tuberculosis, the etiological agent for the tuberculosis disease, is a bacterial pathogen thought to infect about a quarter of the global human population. It is the first cause of death among infectious diseases, and is most prevalent in low ...

EPFL2020

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

Near-field characterization of Bloch surface waves based 2D optical components

Richa Dubey

Bloch surface waves (BSWs) are surface electromagnetic modes that propagate at the interface between a multilayer substrate and a homogeneous external medium. The optical field of the surface mode is confined near the surface of the multilayer. This vertic ...

EPFL2017

Scaling effect and its impact on wavelength-scale microlenses

Hans Peter Herzig, Toralf Scharf, Myun Sik Kim

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

On the Limits of Precision Glass Molding for Diffractive Optical Elements

Karin Prater

Diffractive optical elements (DOEs) consist of surface reliefs with dimensions in the micrometer range and nanometer precision. Two technologies dominate: Elements replicated in plastic and directly microfabricated elements in fused silica. Plastic DOEs ar ...

EPFL2017

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

STED imaging of green fluorescent nanodiamonds containing nitrogen-vacancy-nitrogen centers

Demetri Psaltis, Grégoire Pierre Jean Laporte

We report Stimulated Emission Depletion (STED) imaging of green fluorescent nanodiamonds containing Nitrogen-Vacancy-Nitrogen (NVN) centers with a resolution of 70 nm using a commercial microscope. Nanodiamonds have been demonstrated to have the potential ...

Optical Soc Amer2016

Simple and easily controllable parabolic-shaped microlenses printed on polymeric mesas

Jürgen Brugger, Joo Yeon Kim, Cristina Martin Olmos

A simple and easy shape-controllable approach is demonstrated for the fabrication of parabolic-shaped polymer microlenses (mu-lenses), which are widely used in bio-imaging systems such as microfluidic and lab-on-a-chip systems for improving the image quali ...

Royal Society of Chemistry2013

Observation of Axial Phase Evolution of Highly Confined Light Fields

Hans Peter Herzig, Toralf Scharf, Myun Sik Kim

Highly confined light fields demonstrate peculiar phase features, e.g., Gouy phase anomaly. Longitudinal-differential phase measurements by a high-resolution interference microscope are applied to investigate phase evolutions of confined light fields for p ...

2011

Quantitative phase restoration by direct inversion using the optical transfer function

Christian Depeursinge, Pierre Marquet, Shanshan Kou, Laura Waller

Quantitative phase recovery of phase objects is achieved by a direct inversion using the defocused weak object transfer function. The presented method is noniterative and is based on partially coherent principles. It also takes into account the optical pro ...

Optical Society of America2011

Microlenses with defined contour shapes

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

Ink-jet printing of optical ink over SU-8 pillars is here proposed as a technology for obtaining microlenses with shape control. To demonstrate the flexibility of this method, microlenses with five different contour shapes (ranging from circular and ellipt ...

Optical Society of America2011

Optical Plasmonic Trapping : Effective, Versatile and Compact

Lina Huang

This work focuses on trapping subwavelength objects using resonant plasmonic structures. Trapping entities include latex spheres, living cells and metallic particles; the plasmonic structures involved include subwavelength disks, subwavelength apertures, a ...

EPFL2010

Two step process for the fabrication of diffraction limited concave microlens arrays

Hans Peter Herzig, Irène Antoinette Philipoussis, Toralf Scharf

A two step process has been developed for the fabrication of diffraction limited concave microlens arrays. The process is based on the photoresist filling of melted holes obtained by a preliminary photolithography step. The quality of these microlenses has ...

2008

Inkjet Printing of SU-8; A Case Study for Microlenses

Jürgen Brugger, Edoardo Charbon, Alcherio Martinoli, Dmitri Boiko, Vahid Fakhfouri, Grégory Mermoud, Joo Yeon Kim, Nicolas Cantale

This paper describes a novel method to fabricate polymer MEMS based on the inkjet printing of SU-8, with a special emphasis on integrated micro-optical lens arrays. Inkjet control parameters are optimized in order to enable a stable and reproducible ejecti ...

2008

Inkjet printing of SU-8 for polymer-based MEMS a case study for microlenses

Jürgen Brugger, Vahid Fakhfouri, Edoardo Charbon, Joo Yeon Kim, Grégory Mermoud

This paper describes a novel method to fabricate polymer MEMS based on the inkjet printing of SU-8, with a special emphasis on integrated micro-optical lens arrays. Inkjet control parameters are optimized in order to enable a stable and reproducible ejecti ...

IEEE2008