Publication

Theoretical Investigation of the Radiation Pattern From LEDs Incorporating Shallow Photonic Crystals

Publications associées (31)

On the Complete Radiation Pattern of a Vertical Hertzian Dipole Above a Low-Loss Ground

The complete radiation field pattern of a vertical Hertzian dipole antenna on or above a lossless or low-loss dielectric half-space is studied using a rigorous Sommerfeld formalism. The reflected fields in the air above the interface and the subsurface fie ...

Ieee-Inst Electrical Electronics Engineers Inc2021

Crystallization kinetics of atomic crystals revealed by a single-shot and single-particle X-ray diffraction experiment

Giorgio Rossi, Christoph Bostedt, Alessandro Colombo

Crystallization is a fundamental natural phenomenon and the ubiquitous physical process in materials science for the design of new materials. So far, experimental observations of the structural dynamics in crystallization have been mostly restricted to slo ...

National Academy of Sciences2021

Single-Sensor EMI Source Localization Using Time Reversal: An Experimental Validation

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Hamidreza Karami, Zhaoyang Wang

The localization of electromagnetic interference (EMI) sources is of high importance in electromagnetic compatibility applications. Recently, a novel localization technique based on the time-reversal cavity (TRC) concept was proposed using only one sensor, ...

2021

Remarkable Color Gamut Enhancement of Dye Lacquers Using Corrugated Surfaces

Olivier Martin, Sebastian Mader

The visual appearance of any colorized object is usually determined by the spectral absorption of either pigments or dyes. One can however also colorize objects with structural colors that typically have an iridescent appearance, as seen on many beetles. T ...

2021

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

Hydraulic fracture growth in quasi-brittle materials

Dong Liu

Hydraulic fracturing is a technique often used in the oil and gas industry to enhance the production of wells in low-permeability reservoirs. It consists of fluid injection at a sufficiently large injection rate to create and propagate tensile fractures in ...

EPFL2021

Light pattern generation with hybrid refractive microoptics under Gaussian beam illumination

Toralf Scharf, Maryam Yousefi

The generation of wide-angle diffraction patterns can be done in different ways using either thin diffractive optical elements with small features sizes or arrays of microoptics with large optical paths that are thick diffractive optical elements. Our aim ...

2020

Refinement for single-nanoparticle structure determination from low-quality single-shot coherent diffraction data

Christophe Nicolas, Christoph Bostedt

With the emergence of X-ray free-electron lasers, it is possible to investigate the structure of nanoscale samples by employing coherent diffractive imaging in the X-ray spectral regime. In this work, we developed a refinement method for structure reconstr ...

INT UNION CRYSTALLOGRAPHY2020

Diffraction artefacts from twins and stacking faults, and the mirage of hexagonal, polytypes or other superstructures

Cyril Cayron

Recently, a hexagonal phase has been reported in high carbon steels in several studies. Here, we show that the electron microscopy results used in these studies were erroneously interpreted. The extra-spots in the diffraction patterns and the odd contrasts ...

2020

Adjoint method and inverse design for diffractive beam splitters

Toralf Scharf, Dong Cheon Kim

Diffractive optical elements with a large diffraction angle require feature sizes down to sub-wavelength dimensions, which require a rigorous electromagnetic computational model for calculation. However, the computational optimization of these diffractive ...

SPIE-INT SOC OPTICAL ENGINEERING2020

Imaging plasma formation in isolated nanoparticles with ultrafast resonant scattering

Daniela Rupp, Christoph Bostedt, Alessandro Colombo

We have recorded the diffraction patterns from individual xenon clusters irradiated with intense extreme ultraviolet pulses to investigate the influence of light-induced electronic changes on the scattering response. The clusters were irradiated with short ...

2020