Publications associées à Diapason

A Wide-Frequency-Tuning Micro-Loop-Gap Resonator for Miniature Rubidium Vapor-Cell Atomic Frequency Standards

To miniaturize the double-resonance (DR) rubidium (Rb) vapor-cell atomic clocks, a new type of micro-loop-gap microwave resonator (mu-LGR) is proposed for TE011-like mode where the magnetic field inside the cavity is homogeneous and oriented along its long ...

Institute of Electrical and Electronics Engineers2023

Programmable Silicon Nitride Photonic Integrated Circuits

Tobias Kippenberg, Rui Ning Wang, Anat Siddharth, Viacheslav Snigirev, Andrea Bancora, Andrey Voloshin, Vladimir Shadymov

Silicon Nitride (Si3N4) photonic integrated circuits (PICs) have emerged as core technology in a variety of applications ranging from LIDAR to quantum control and computing. However, the need for high-speed, low-voltage tuning and modulation has been a lon ...

IEEE2023

Sub-kHz-Linewidth External-Cavity Laser (ECL) With Si3N4 Resonator Used as a Tunable Pump for a Kerr Frequency Comb

Tobias Kippenberg, Junqiu Liu

Combining optical gain in direct-bandgap III-V materials with tunable optical feedback offered by advanced photonic integrated circuits is key to chip-scale external-cavity lasers (ECL), offering wideband tunability along with low optical linewidths. Exter ...

IEEE Institute of Electrical and Electronics Engineers2023

Effects of resonator geometry and substrate stiffness on the tunability of a deformable microwave metasurface

Romain Christophe Rémy Fleury, Rayehe Karimi Mahabadi, Taha Goudarzi

Tunable metasurfaces can shift their resonant frequency through different approaches, one of which is applying mechanical deformations. Here, we show the effects of two key factors on the tunability of deformable metasurfaces; the resonator geometry and su ...

2022

Shaking force balancing of a 2-DOF isotropic horological oscillator

Simon Nessim Henein, Hubert Pierre-Marie Benoît Schneegans, Etienne Frédéric Gabriel Thalmann

Despite centuries of research and significant advances, the escapement mechanism used to count and maintain oscillations of mechanical time bases remains a complex mechanism and a major source of energy losses. We showed in previous work that, instead of t ...

2021

Basic design considerations for a frequency step-tunable electron cyclotron wave system to suppress NTMs in DEMO

Minh Quang Tran, Emiliano Fable, Hartmut Zohm, Emanuele Poli, Konstantinos Avramidis, Giovanni Tardini

An Electron Cyclotron Wave (ECW) system will be used in the European DEMO for the stabilization of Neoclassical Tearing Modes (NTMs). In order to avoid movable mirrors in the harsh environment close to the plasma and to simplify the NTM launcher integratio ...

2021

Flexure Pivot Oscillators for Mechanical Watches

Etienne Frédéric Gabriel Thalmann

It appears that the concerted efforts of the watchmaking industry are leading towards a limit in mechanical watch accuracy. The general consensus in horology is that the time base's quality factor, a dimensionless number that characterizes the oscillator d ...

EPFL2020

Thermo-optic tuning of spectral broadening in a nonlinear Ultra-Silicon-Rich Nitride grating

Jae-Woo Choi

Temperature tuning of spectral broadening induced by a nonlinear grating is experimentally demonstrated. The bandwidth is observed to decrease as temperature increases, corresponding to a red-shift in the high dispersion region of the Bragg grating. ...

IEEE2020

Scanning near-field optical microscopy with new probes and feedback modes

Anton Smirnov

Scanning Near-field Optical Microscopy (SNOM) technique enables to overcome Abbe diffraction limit of far-field optics as well as to obtain simultaneously optical and topographical images. While the optical resolution of the method is limited by the apertu ...

EPFL2019

Long-life plastic optical fiber probes for scanning near-field optical microscope

Giovanni Dietler, Serguei Sekatski, Anton Smirnov, Ekaterina Rostova

Nowadays, sharpened glass fiber - made probes attached to a quartz tuning fork (TF) and exploiting the shear force - based feedback are by far the most popular in the field of SNOM. These probes are expensive, very fragile and their fabrication is difficul ...

SPIE-INT SOC OPTICAL ENGINEERING2018

Port: A Piezoelectric Optical Resonance Tuner

Tobias Kippenberg, Michail Zervas

This abstract presents an aluminum nitride (AlN) piezoelectric actuator for tuning optical resonance modes of silicon nitride photonic resonators. The AlN actuator is fabricated on top of a thick silicon dioxide cladding that encapsulates the nitride reson ...

IEEE2018

Slow dynamics in structured neural network models

Samuel Pavio Muscinelli

Humans and some other animals are able to perform tasks that require coordination of movements across multiple temporal scales, ranging from hundreds of milliseconds to several seconds. The fast timescale at which neurons naturally operate, on the order of ...

EPFL2018

Recent improvements on micro-thermocouple based SThM

Danick Briand

The scanning thermal microscope (SThM) has become a versatile tool for local surface temperature mapping or measuring thermal properties of solid materials. In this article, we present recent improvements in a SThM system, based on a micro-wire thermocoupl ...

Iop Publishing Ltd2017

Design Techniques for Ultra High Frequency Clock Generation in 28 nm FDSOI Technology

Hasene Gülperi Özsema

Twentieth century has been the golden age of semiconductor industry by achieving a high level of growth as a courtesy of developments in fabrication techniques and downscaling of the technology. Since the downscaling in current lithography technology is re ...

EPFL2017

Tuning the resonance frequencies and mode shapes in a large range multi-degree of freedom micromirror

Matthias Imboden

The ability to actively shift the primary resonance of a 2D scanning micromirror allows the user to set the scanning direction, set the scanning frequency, and lift otherwise degenerate modes in a symmetrically designed system. In most cases, resonant scan ...

Optical Soc Amer2017

In vivo evaluation of a novel, wrist-mounted arterial pressure sensing device versus the traditional hand-held tonometer

Orestis Vardoulis

Although hemodynamic parameters can be assessed non-invasively, state-of-the-art non-invasive systems generally require an expert operator and are not applicable for ambulatory measurements. These limitations have restricted our understanding of the contin ...

Elsevier Sci Ltd2016

Graphene Quantum Capacitors for High Frequency Tunable Analog Applications

Juan Ramon Mosig, Mihai Adrian Ionescu, Clara-Fausta Moldovan, Michele Tamagnone, Pankaj Sharma, Wolfgang Amadeus Vitale

Graphene quantum capacitors (GQC) are demonstrated to be enablers of radio-frequency (RF) functions through voltage-tuning of their capacitance. We show that GQC complements MEMS and MOSFETs in terms of performance for high frequency analog applications an ...

American Chemical Society (ACS)2016

Acoustic carpet cloak based on an ultrathin metasurface

Juan Ramon Mosig, Hervé Lissek, Sami Driss Karkar, Seyyed Hussein Seyyed Esfahlani

An acoustic metasurface carpet cloak based on membrane-capped cavities is proposed and investigated numerically. This design has been chosen for allowing ultrathin geometries, although adapted to airborne sound frequencies in the range of 1 kHz (λ≈30 cm), ...

Amer Physical Soc2016

Living on the Edge: Re-shaping the Interface of Synthetic Biology and Nanotechnology

Ardemis Anoush Boghossian, Shang-Jung Wu

A new team of researchers at EPFL is taking an 'anti-disciplinary' approach to creating optical devices. These devices take advantage of the synergy in tuning both nano- and bio-material properties, coupling 'the advantages of two growing, albeit tradition ...

Schweizerische Chemische Gesellschaft2016

A Wide Tuning Range 4th-Order Gm-C Elliptic Filter for Wideband Multi-Standards GNSS Receivers

Pierre-André Farine, Cyril Botteron, Gabriele Tasselli, Saeed Ghamari

A 4 th order Gm-C elliptic low-pass filter with a wide continuous tuning range is presented. The continuous tuning is achieved by means of a new tuning circuit which adjusts the bias current of the Gm cell's input stage to control the cut-off frequency. Wi ...

IEEE2015