Publications related to Focus (optics)

Ghost imaging using two SPAD array detectors: a parameter study towards the realization of a 3D quantum microscope

Edoardo Charbon, Claudio Bruschini, Paul Mos, Yang Lin

Quantum ghost imaging can be an important tool in making optical measurements. One of the most useful aspects of ghost imaging is the unique ability to correlate two sets of independently collected information. We aim to use the principles of ghost imaging ...

Spie-Int Soc Optical Engineering2024

Transfer learning application of self-supervised learning in ARPES

Gabriel Aeppli

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

A Data-Driven Fault Location Algorithm Based on the Electromagnetic Time Reversal in Mismatched Media

Mario Paolone, Zhaoyang Wang, Zhe Chen

The classical electromagnetic time reversal (EMTR) fault location method in power systems can be time consuming, especially when a high location accuracy is desired. To cope with this issue, the concept of EMTR in mismatched media has recently been introdu ...

2021

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

Laser engraving device for multiple laser beams

Andreas Schueler, Luc Burnier

The present invention concerns a laser engraving device (1) for engraving a target surface (17). The laser engraving device (1) comprises: a beam splitter (7) for dividing a processing laser beam (25) into a plurality of engraving laser beams (27); a first ...

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

Ultrasensitive hyperspectral imaging and biodetection enabled by dielectric metasurfaces

Volkan Cevher, Hatice Altug, Filiz Yesilköy, Andreas Tittl, Yasaman Jahani, Eduardo Romero Arvelo, Mingkai Liu

Metasurfaces based on resonant subwavelength photonic structures enable novel ways of wavefront control and light focusing, underpinning a new generation of flat-optics devices. Recently emerged all-dielectric asymmetric metasurfaces, composed of arrays of ...

Nature Publishing Group2019

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

Toralf Scharf, Wilfried Noell, 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

Light refocusing with up-scalable resonant waveguide gratings in confocal prolate spheroid arrangements

Olivier Martin, Benjamin Gallinet, Zdenek Benes, Giorgio Quaranta, Guillaume Basset

Resonant waveguide gratings (RWGs) are thin-film structures, where coupled modesinterfere with the diffracted incoming wave and produce strong angular and spectral filtering. The combination of two finite-length and impedance matched RWGs allows the creati ...

2018

The multi-spectral imaging diagnostic

Basil Duval, Christian Gabriel Theiler, Yanis Andrebe, Kevin Henricus Annemarie Verhaegh, Mirko Wensing

The Multi-Spectral Imaging system is a new diagnostic that captures simultaneous spectrally filtered images from a common line of sight while maintaining a large etendue and high throughput. Imaging several atomic line intensities simultaneously may enable ...

2018

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

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

Interferometric study on Gouy phase anomaly of microlens array

Hans Peter Herzig, Toralf Scharf, Wilfried Noell, Myun Sik Kim

We investigate the Gouy phase anomaly of light in the focus of refractive plano-convex microlens arrays by using longitudinal-differential (LD) interferometry and a finite-difference time-domain (FDTD) simulation. We put emphasis on determining the amount ...

Spie-Int Soc Optical Engineering2015

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, 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

Synergy of hyperspectral and microwave remote sensing data to derive bio- and geo-physical parameters for land applications

Jelena Stamenkovic

Retrieval of bio/geophysical variables from remote sensing imagery is an important research field. Due to the development and availability of different EO satellites, especially the ones with hyperspectral sensors, the combined use of radar and optical ima ...

EPFL2015

Enhanced resolution in a multimode fiber imaging system

Demetri Psaltis, Christophe Moser, Nicolino Stasio, Grégoire Pierre Jean Laporte

Multimode fibers have recently been demonstrated to be a promising candidate for ultrathin and high resolution endoscopy. However, this method does not offer depth discrimination for fluorescence imaging and the numerical aperture of the fiber limits its r ...

Optical Soc Amer2015

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

Ultrafast All-Polymer Electrically Tunable Silicone Lenses

Herbert Shea, Samuel Rosset, Luc Maffli, Michele Ghilardi

Dielectric elastomer actuators (DEA) are smart lightweight flexible materials integrating actuation, sensing, and structural functions. The field of DEAs has been progressing rapidly, with actuation strains of over 300% reported, and many application conce ...

Wiley-Blackwell2015