Publications associées à High power ultraviolet LED illumination systems: coherence properties and applications in photolithography

III-N blue-emitting epi-structures with high densities of dislocations: Fundamental mechanisms for efficiency improvement and applications

Since the dawn of humanity, human beings seeked to light their surroundings for their well-being, security and development. The efficiency of ancient lighting devices, e.g. oil lamps or candles, was in the order of 0.03-0.04% and jumped to 0.4-0.6% with th ...

EPFL2024

3D diffractive optics for linear interconnects and nonlinear processing

Niyazi Ulas Dinç

The optical domain presents potential avenues for enhancing both computing and communication due to its inherent properties of bandwidth, parallelism, and energy efficiency. This research focuses on harnessing 3-Dimensional (3D) diffractive optics for nove ...

EPFL2024

Printed ecoresorbable temperature sensors for environmental monitoring

Danick Briand, James Alec Pierce Bourely, Nicolas Francis Fumeaux, Melissa Kossairi

Electronic waste has become a pressing issue, necessitating sustainable solutions for the disposal of electronic devices. While the development of environmentally degradable electronics has gained attention, the fabrication of stable and performant sensors ...

2023

Ion-Dipole Interaction Enabling Highly Efficient CsPbI3 Perovskite Indoor Photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Di Zhang, Meng Li, Xiaoyan Wang, Haizhou Lu, Xingyu Gao, Ziyun Wang, Jie Chen

Metal halide perovskites are ideal candidates for indoor photovoltaics (IPVs) because of their easy-to-adjust bandgaps, which can be designed to cover the spectrum of any artificial light source. However, the serious non-radiative carrier recombination und ...

Wiley-V C H Verlag Gmbh2023

Wideband integrated bioaerosol sensor (WIBS) excited, fluorescent, and hyper-fluorescent particle number concentrations and normalized size distributions (dN/dlogDp) measured in the Swiss container during MOSAiC 2019/2020

Julia Schmale, Ivo Fabio Beck, Margarida Teles Nogueira Rolo, Alireza Moallemi

These datasets contain the total particle number concentrations and normalized size distributions (dN/dlogDp) of excited, fluorescent, and hyper-fluorescent particles of sizes 0.5 to 20 μm (optical diameter). The normalized size distribution datasets are s ...

Zenodo2023

The mesoglea buffers the physico-chemical microenvironment of photosymbionts in the upside-down jellyfish Cassiopea sp

Anders Meibom, Niclas Heidelberg Lyndby, Michael Kühl

IntroductionThe jellyfish Cassiopea has a conspicuous lifestyle, positioning itself upside-down on sediments in shallow waters thereby exposing its photosynthetic endosymbionts (Symbiodiniaceae) to light. Several studies have shown how the photosymbionts b ...

FRONTIERS MEDIA SA2023

Perceived glare from the sun behind tinted glazing: Comparing blue vs. color-neutral tints

Marilyne Andersen, Andreas Schueler, Jan Wienold, Maxime Lagier, Sneha Jain

While the influence of a glare source's spectrum on sensitivity to discomfort glare has been demonstrated repeatedly under electric light conditions, it has not yet been studied under actual daylit conditions. To investigate the influence of spectral alter ...

2023

First developments towards producing inductive magnetic sensors using state-of-the-art photolithography techniques

Duccio Testa, Ambrine Douhane, Marcus Cemes

Inductive magnetic sensors are needed for tokamak operation to provide the low-frequency (LF) measurements leading to the equilibrium reconstruction and to monitor the higher frequency (HF) instabilities; the HF magnetic sensors are often also used as a ba ...

2023

High-efficiency non-ablative UV laser nano-scale processing of fused silica by stable filamentation

Yves Bellouard, Olivier Bernard, Benedikt Hermann, Luca Muscarella

Over the last decades, three-dimensional micro-manufacturing of fused silica via near-infrared ultrafast laser exposure combined with an etching step has become an established technique for producing complex three-dimensional components. Here, we explore t ...

2023

The physics of 3D printing with light

Christophe Moser

The goal of 3D printing is to realize complex 3D structures by locally adding material in small volume elements called voxels - in contrast to successively subtracting material by etching, milling or machining. This field started with optics-based proposal ...

Nature Portfolio2023

Laser-Induced Forward Transfer of Functional Microdevices

Zhiwei Yang

Laser-induced forward transfer (LIFT) technique is an emerging micro additive manufacturing (AM) technique that has been widely used to print a variety of materials. Distinguished from other nozzle-based AM techniques, LIFT operates without the existence o ...

EPFL2023

Photochemical Alkynylations with Hypervalent Iodine Reagents

Stephanie Grace Elizabeth Amos

Over the past twenty years, photochemical transformations have gained in importance in organic chemistry. Indeed, the development of photocatalysts has allowed the use of visible light as an energy source for chemical transformations. More specifically, ph ...

EPFL2022

Visual comfort without borders: Extending daylight glare prediction to dim daylit environments

Geraldine Cai Ting Quek

Avoiding discomfort glare is one of the critical aspects of maintaining visual comfort, which significantly influences occupants' overall satisfaction with their indoor environment. Discomfort glare prediction models have been developed for various lightin ...

EPFL2022

Effects of illuminance intensity on the green channel of remote photoplethysmography (rPPG) signals

Ata Jedari Golparvar

Point-of-care remote photoplethysmography (rPPG) devices that utilize low-cost RGB cameras have drawn considerable attention due to their convenience in contactless and non-invasive vital signs monitoring. In rPPG, sufficient lighting conditions are essent ...

SPRINGER2022

Photonic nanostructures mimicking floral epidermis for perovskite solar cells

Mohammad Khaja Nazeeruddin, Hobeom Kim

Here, we report photonic nanostructures replicated from the adaxial epidermis of flower petals onto light-polymerized coatings using low-cost nanoimprint lithography at ambient temperature. These multifunctional nanocoatings are applied to confer enhanced ...

ELSEVIER2022

Separation and Recycling Potential of Rare Earth Elements from Energy Systems: Feed and Economic Viability Review

Christian Ludwig, Rudolf Paul Wilhelm Jozef Struis, Viktoria Paetzel, Ajay Bhagwan Patil

This review explores the potential of separating and recycling rare earth elements (REEs) from different energy conversion systems, such as wind turbines, electric vehicles batteries, or lighting devices. The REEs include 17 elements (with global productio ...

2022

Room-temperature electrical control of polarization and emission angle in a cavity-integrated 2D pulsed LED

Andras Kis, Dmitrii Unuchek, Juan Francisco Gonzalez Marin, Fedele Tagarelli, Cheol Yeon Cheon, Zhe Sun

Devices based on two-dimensional (2D) semiconductors hold promise for the realization of compact and versatile on-chip interconnects between electrical and optical signals. Although light emitting diodes (LEDs) are fundamental building blocks for integrate ...

Nature Research2022

Validation of spectral simulation tools in the context of ipRGC-influenced light responses of building occupants

Marilyne Andersen, Clotilde Marie A Pierson

With the growing awareness about ipRGC-influenced light (IIL) responses, design applications related to these responses are flourishing. To compare design options and optimize lighting conditions for building occupants, lighting simulations are typically u ...

2023

Optical Diffraction Tomography Using Nearly In-Line Holography with a Broadband LED Source

Demetri Psaltis, Ahmed Ayoub, Abhijit Roy

We present optical tomography methods for a 3D refractive index reconstruction of weakly scattering objects using LED light sources. We are able to record holograms by minimizing the optical path difference between the signal and reference beams while sepa ...

MDPI2022

Theory and application of a data-driven approach to compressive spectrometry in the assessment of neurophotic stimulation

Forrest Simon Webler

Recent advances in biology and neuroscience have elucidated pathways in which visible light initiates a signaling process, via the eye, responsible for activating direct and indirect biological responses. While the full impact of unnatural light patterns o ...

EPFL2022