Publications associées à Cercle de confusion

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

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

Learning stereo reconstruction with deep neural networks

Stepan Tulyakov

Stereo reconstruction is a problem of recovering a 3d structure of a scene from a pair of images of the scene, acquired from different viewpoints. It has been investigated for decades and many successful methods were developed. The main drawback of these ...

EPFL2020

Solving the Depth Ambiguity in Single-Perspective Images

Sabine Süsstrunk, Majed El Helou, Marjan Shahpaski

Scene depth estimation is gaining in importance as more and more AR/VR and robot vision applications are developed. Conventional depth-from-defocus techniques can passively provide depth maps from a single image. This is especially advantageous for moving ...

2019

Fourier light scattering model for treating textures deeper than the wavelength

Christophe Ballif, Franz-Josef Haug, Matthias Wolfgang Bräuninger

We apply a Fourier-scattering model to describe light scattering in solar cells with textured surfaces. For the size and inclination angle of typical micro-textures, scattering may occur into large angles. This makes the model prone to paraxial errors. We ...

Optical Society of America2017

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

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

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

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

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