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Publications associées (32)

Wavelength-stabilized figure-of-9 thulium-doped all-fiber laser emitting 560 fs pulses

Camille Sophie Brès, Moritz Bartnick, Gayathri Bharathan

We demonstrate a figure-of-9 all-fiber thulium-doped laser (TDFL) that generates 560 fs long pulses at 1948 nm wavelength. In order to achieve self-starting passive mode-locking, we utilize an in-fiber Faraday rotator to induce a nonreciprocal phase shift. ...

Iop Publishing Ltd2024

Modeling and optimization of PCB coils for inductive power transfer systems

Xiaotong Du

The auxiliary power supply for medium voltage converters requires high insulation capability between the source and the load. Inductive power transfer technology, with an air gap between the primary and secondary coil, offers such high insulation capabilit ...

EPFL2024

A modular multiple frequency inductive link to wirelessly power multiple miniaturized implants

Sandro Carrara, Diego Ghezzi, Gian Luca Barbruni

A modular multiple frequency coils inductive link system to wirelessly provide power for at least a medical implant at an output of a receiving coil, whereby the receiving coil is configured to be implanted in an organism. The modular multiple frequency co ...

2024

Waveguide amplifier and waveguide amplifier fabrication method

Tobias Kippenberg, Xinru Ji, Zheru Qiu, Yang Liu

The present invention concerns a waveguide amplifier comprising: - at least one embedding cladding material or layer, and - at least one rare-earth ion implanted silicon nitride material or layer embedded in the at least one embedding cladding material or ...

2023

Biomaterial devices on Arecanut palm leaf for microwave applications

Anja Skrivervik, Sujith Raman

This paper presents an investigation on the possibility of arecanut palm leaf as a biomaterial substrate for various microwave devices such as transmission lines, antenna, filter and a radio frequency identification device (RFID). The dielectric properties ...

IEEE2023

Microstrip patch antennas with broad beamwidth

Ismael Vico Triviño

Microstrip antennas offer a broad set of advantages such as low profile, light weight, easy fabrication and low cost. As these are desirable or even critical for a broad range of applications, there has been a large interest for these antennas in the anten ...

EPFL2023

Time-Domain Integration of Broadband Terahertz Pulses via Tapered Two-Wire Waveguide

Alessandro Tomasino

In this work, we report on the implementation of a time-domain integrator device operating on arbitrary broadband Terahertz (THz) pulses. This analog signal-processing functionality is implemented by employing a two-wire waveguide (TWWG) variant, based on ...

IEEE2023

4-Port Microstrip planar resonator for multiband microwave material characterization applications

Anja Skrivervik, Sujith Raman

Planar microstrip resonators suitable for material characterization application are presented in this paper. The prototype consists of three resonators fed through four ports in a planar dielectric substrate without any additional resonators. The resonator ...

IEEE2022

Performance Analysis of Energy Balancing Methods for Matrix Modular Multilevel Converters

Drazen Dujic, Stefan Milovanovic, Philippe Alexandre Bontemps

Modular multilevel converters achieve voltage scalability through the series connection of cells, each with its own capacitance. However, this converter structure using floating energy storage elements increases the control complexity significantly. The vo ...

2022

Lock-in amplified differential phase contrast

Christophe Moser, Damien Claude-Marie Loterie, Timothé Laforest, Chiara Bonati

We introduce a lock-in method to increase the phase contrast in incoherent Differential Phase Contrast (DPC) imaging. The use of a smart pixel detector with in-pixel signal demodulation, paired with synchronized illumination, provides the basis of a bit-ef ...

SPIE-INT SOC OPTICAL ENGINEERING2022

Unconventional time-bandwidth performance of resonant cavities with nonreciprocal coupling

Camille Sophie Brès, Davide Grassani, Kosmas Tsakmakidis, Ivan Cardea

The time-bandwidth limit is a mathematical tenet that affects all reciprocal resonators, stating that the product of the spectral bandwidth that can couple into a resonant system and its characteristic energy decay time is always equal to 1. Here, we devel ...

2021

Probing unconventional performance of fiber resonators: light storage, generation and manipulation

Ivan Cardea

This thesis aims at investigating the performance of figure-9 (figure-of-nine) optical fiber resonators as a practical solution for light storage, light generation and manipulation. The first part of the thesis focuses on a theoretical and experimental stu ...

EPFL2021

Towards a N77 Electroacoustic Filter Using Thin Films of Crystalline Y-cut Lithium Niobate

Luis Guillermo Villanueva Torrijo, Soumya Yandrapalli

This paper presents the use of a novel type of resonators made of a thin membrane of Y-cut Lithium Niobate that has an array of interdigitated electrodes on the top, and a floating metal on the bottom. Each electrode gives rise to a quasi-independent reson ...

IEEE2021

Smooth GaN membranes by polarization-assisted electrochemical etching

Nicolas Grandjean, Jean-François Carlin, 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

Ultralow-Profile Circularly Polarized Reflectarray Antenna for CubeSat Intersatellite Links in K-B and

Anja Skrivervik, Miroslav Veljovic

An ultralow-profile circularly polarized (CP) reflectarray (RA) antenna is presented in this article, based on the variable-rotation technique for beam collimation and scanning. Starting from a conventional split-loop element, a new wideband element is des ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2021

A Cryogenic Broadband Sub-1-dB NF CMOS Low Noise Amplifier for Quantum Applications

Edoardo Charbon, Andrea Ruffino, Yatao Peng

A cryogenic broadband low noise amplifier (LNA) for quantum applications based on a standard 40-nm CMOS technology is reported. The LNA specifications are derived from the readout of semiconductor quantum bits at 4.2 K, whose quantum information signals ar ...

2021

Sommerfeld Integrals and Their Relation to the Development of Planar Microwave Devices

Juan Ramon Mosig, Krzysztof Michalski

This paper deals with the mathematical expressions called Sommerfeld integrals. Introduced by A. Sommerfeld in 1909, they are mathematically equivalent to inverse Hankel transforms. The original historical goal of these integrals was to provide an accurate ...

Ieee-Inst Electrical Electronics Engineers Inc2021

Temporal Modulation of Bianisotropic Metasurfaces for Unidirectional Wave Amplification

Xiaoqiang Wang, Mohammad Sajjad Mirmoosa

Nonreciprocity in time-modulated metasurfaces is normally achieved only when it is combined with with space modulation, using at least two time-varying elements located at different positions in space. In this talk, we present the idea of time-modulated bi ...

IEEE2020

97.4%-Efficient All-GaN Dual-Active-Bridge Converter with High Step-up High-Frequency Matrix Transformer

Elison de Nazareth Matioli, Armin Jafari, Mohammad Samizadeh Nikooytabalvandani, Palliyage Srilak Nirmana Perera

In this work, we demonstrate a state-of-the-art high step-up/down dual-active-bridge (DAB) converter designed with GaN transistors, to achieve a high efficiency and large power-density. A quasi-planar matrix transformer with high step-up/down ratio is demo ...

2020

Nonreciprocity in Bianisotropic Systems with Uniform Time Modulation

Xiaoqiang Wang, Mohammad Sajjad Mirmoosa

Physical systems with material properties modulated in time provide versatile routes for designing magnetless nonreciprocal devices. Traditionally, nonreciprocity in such systems is achieved exploiting both temporal and spatial modulations, which inevitabl ...

AMER PHYSICAL SOC2020