Publications associées à Polarization Properties of Columnar Quantum Dots: Effects of Aspect Ratio and Compositional Contrast

Parametric Wavelength Conversion in Waveguiding Structures: Efficiency, Bandwidth and Polarization

Photonics integrated circuits are a promising solution for the growing demands of data transmission and future system-on-chip technologies. Within this context, nonlinear optical interactions offer unique opportunities for all-optical processing, sampling, ...

EPFL2024

Measuring electrical properties in semiconductor devices by pixelated STEM and off-axis electron holography (or convergent beams vs. plane waves)

Victor Carle Adrien Boureau

We demonstrate the use of both pixelated differential phase contrast (DPC) scanning transmission electron microscopy (STEM) and off-axis electron holography (EH) for the measurement of electric fields and assess the advantages and limitations of each techn ...

Pergamon-Elsevier Science Ltd2024

Polarization-enhanced GaN Schottky barrier diodes: Ultra-thin InGaN for high breakdown voltage and low Ron

Elison de Nazareth Matioli, Alessandro Floriduz, Zheng Hao

In this work, we present a concept that leverages the strong piezoelectric polarization field in InGaN, which counteracts the external electric field at reverse bias. We show that despite the smaller InGaN band-gap and lower critical electric field, its st ...

2024

Physical insights from the aspect ratio dependence of turbulence in negative triangularity plasmas

Stefano Coda, Justin Richard Ball

In this work, we study the impact of aspect ratio A = R 0 / r (the ratio of major radius R 0 to minor radius r) on the confinement benefits of negative triangularity (NT) plasma shaping. We use high-fidelity flux tube gyrokinetic GENE simulations and consi ...

Iop Publishing Ltd2024

Circularly polarized planar antenna with axially symmetric beamwidth reconfigurability

Anja Skrivervik, Ismael Vico Triviño, Hannes Bartle

This contribution presents the design of a compact circularly polarized antenna featuring beamwidth reconfiguration in both the horizontal and vertical planes. The observed radiation patterns in each of the reconfigurable states present axial symmetry and ...

IEEE2023

Layered metals as polarized transparent conductors

Philip Johannes Walter Moll, Matthias Carsten Putzke, Chunyu Guo, Maja Deborah Bachmann

The quest to improve transparent conductors balances two key goals: increasing electrical conductivity and increasing optical transparency. To improve both simultaneously is hindered by the physical limitation that good metals with high electrical conducti ...

Nature Portfolio2023

Domain Imaging and Switching Dynamics in BaTiO3-Based Photonic Integrated Devices

Jacqueline Geler Kremer

Keeping up with our constantly connected lifestyle of instant messages and video streaming has its repercussions. Data centers have been gobbling up resources becoming a significant share of the energy used worldwide. To keep up with demand and curb the en ...

EPFL2023

Exploring Novel Modalities for Optical Diffraction Tomography

Amirhossein Saba Shirvan

In the past decade, optical diffraction tomography has gained a lot of attention for its ability to create label-free three-dimensional (3D) images of the refractive index distribution of biological samples using scattered fields measured through holograph ...

EPFL2023

Plasmonic nanobar-on-mirror antenna with giant local chirality: a new platform for ultrafast chiral single-photon emission

Wen Chen, Kai Wang

Providing an additional degree of freedom for binary information encoding and nonreciprocal information transmission, chiral single photons have become a new research frontier in quantum optics. Without using complex external conditions (e.g., magnetic fie ...

ROYAL SOC CHEMISTRY2022

Pitfalls in the spectral measurements of polarization-altering metasurfaces

Olivier Martin, Hsiang-Chu Wang

The optical characterization of metasurfaces and nanostructures that alter the polarization of light is tricky and can lead to unphysical results, such as reflectance beyond unity. We track the origin of such pitfalls to the response of some typical optica ...

Optica Publishing Group2022

Energy correlators of hadronically decaying electroweak bosons

Lorenzo Ricci, Marc Riembau Saperas

Energy correlators are field-theoretically clean and phenomenologically valuable probes of QCD dynamics. We explore the possibility of using the information encoded in the energy correlators of a hadronically decaying electroweak vector boson in order to e ...

American Physical Society2022

Enhancing the beamwidth of low profile single-fed microstrip antennas using parasitic elements

Anja Skrivervik, Ismael Vico Triviño

In this paper we present a technique to broaden the beamwidth of conventional patch microstrip antennas by using parasitic elements. This technique allows to keep the main advantages of microstrip antennas while increasing their beamwidth. We provide guide ...

IEEE2022

Performance and reproducibility of C-13 and N-15 hyperpolarization using a cryogen-free DNP polarizer

Hikari Ananda Infinity Yoshihara, Arianna Ferrari

The setup, operational procedures and performance of a cryogen-free device for producing hyperpolarized contrast agents using dissolution dynamic nuclear polarization (dDNP) in a preclinical imaging center is described. The polarization was optimized using ...

Nature Portfolio2022

Optoelectronics based on the spin-valley physics of 2D materials

Juan Francisco Gonzalez Marin

Two-dimensional (2D) materials are atomically thin crystals with exceptional mechanical, electrical and optical properties. Their unique characteristics originating from quantum confinement in the vertical dimension have attracted a strong interest for sci ...

EPFL2022

Smooth GaN membranes by polarization-assisted electrochemical etching

Jean-François Carlin, Nicolas Grandjean, Joachim Armand Simonne Ciers

III-nitride membranes offer promising perspectives and improved device designs in photonics, electronics, and optomechanics. However, the removal of the growth substrate often leads to a rough membrane surface, which increases scattering losses in optical ...

AMER INST PHYSICS2021

Extreme polarization-dependent supercontinuum generation in an uncladded silicon nitride waveguide

Camille Sophie Brès, Eirini Tagkoudi, Caroline Gaëlle Amiot

We experimentally demonstrate the generation of a short-wave infrared supercontinuum in an uncladded silicon nitride (Si3N4) waveguide with extreme polarization sensitivity at the pumping wavelength of 2.1 µm. The air-clad waveguide is specifically designe ...

2021

Spatial statistics of superposition of two uncorrelated speckle patterns with polarization diversity

Abhijit Roy

A detailed theoretical and experimental study on the effect of the superposition of uncorrelated speckle patterns with polarization diversity on the spatial statistics of the superposed speckle pattern is presented. It is shown that depending on the mutual ...

Elsevier2021

Complementary Metasurfaces for Guiding Electromagnetic Wave

Mohammad Sajjad Mirmoosa

Metasurfaces can be employed for designing waveguides that confine the electromagnetic energy while they are open structures. In this communication, we introduce a new type of such waveguides, formed by two penetrable metasurfaces having complementary isot ...

2021

Fabrication and Characterization of High Aspect Ratio Amorphous Silicon Based Microchannel Plates

Christophe Ballif, Nicolas Würsch, Janina Christine Isabelle Löffler, Mohammad Beygi, Samira Alexandra Frey

This contribution focuses on the fabrication and characterization of microchannel plates made of hydrogenated amorphous silicon (AMCPs). Flexible fabrication processes and the semi-conducting nature of amorphous silicon could give these detectors the advan ...

2021

Circularly Polarized Axially Corrugated Feed Horn for CubeSat Reflectarray Applications

Anja Skrivervik, Miroslav Veljovic

Retlectarray (RA) and transmitarray (TA) antennas that use the element-rotation technique require the radiation from the feeding antenna to be circularly polarized (CP). A CP axially corrugated horn antenna is developed as a feeding element for CubeSat RA ...

IEEE2020