Publications associées à Bipolar optical pulse coding for performance enhancement in BOTDA sensors

Magnetism of Single Surface Adsorbed Atoms Studied with Radio-Frequency STM

This thesis investigates the magnetic properties of single atoms and molecules adsorbed on thin magnesium oxide decoupling layers, grown on a silver single crystal. To address these systems experimentally, we use a low temperature scanning tunneling micros ...

EPFL2024

A 0.14-nJ/b 200-Mb/s 2.7-3.5-GHz Quasi-Balanced FSK Transceiver With PLL-Based Modulation and Sideband Energy Detection

Cong Ding, Bowen Wang

This paper describes a balanced frequency shift keying (FSK) modulation, namely quasi-balanced FSK (QB-FSK), for energy-efficient high-data-rate communication. Not suffering from data-pattern dependency, the proposed modulation method enables frequency mod ...

2024

Quench Detection and Temperature Measurement With Fiber Optic Sensors

Davide Uglietti, Kamil Sedlák, Christoph Müller

For the EU DEMO conductor testing, a temperature sensor based on Fiber Bragg Grating (FBG) optical fiber is studied at the EPFL Swiss Plasma Center. The SULTAN test facility has been upgraded to use fiber optic sensor for temperature monitoring and quench ...

IEEE Institute of Electrical and Electronics Engineers2024

Electric-field-induced second-order nonlinear processes in stoichiometric silicon nitride

Boris Zabelich

Nonlinear optical frequency conversion is one of the driving research areas in photonics. Its quasi instantaneous response and the promise of low power consumption in integrated structures could cover the demand for fast signal processing with minimal ener ...

EPFL2024

Live-cell imaging powered by computation

Suliana Manley, Florian Jug

The proliferation of microscopy methods for live-cell imaging offers many new possibilities for users but can also be challenging to navigate. The prevailing challenge in live-cell fluorescence microscopy is capturing intra-cellular dynamics while preservi ...

Nature Portfolio2024

Tunable pump compression and fast modulation for pulsed THz generation

Ileana-Cristina Benea-Chelmus, Shima Rajabali, Yazan Lampert Almahmoud, Alessandro Tomasino

We demonstrate tunable dispersion compensation of femtosecond pulses at telecom wavelengths for broadband Terahertz generation in 7.5-meter fiber link using a Silicon prism pair. The prism pair enhances the amplitude of the THz E-field in InGaAs photocondu ...

IEEE2023

Nanomechanical resonators with low dissipation for quantum optomechanics

Alberto Beccari

Fields of technology as diverse as microwave filter construction, characterization of material interfaces with atomic precision, and detection of gravitational waves from astronomical sources employ mechanical resonators at their core. The utility of mecha ...

EPFL2023

Space-time wave packets with reduced divergence and tunable group velocity generated in free space after multi-mode fiber propagation

Tobias Kippenberg, Hao Song, Maxim Karpov, Xinzhou Su

Previously, space-time wave packets (STWPs) have been gen-erated in free space with reduced diffraction and a tunable group velocity by combining multiple frequency comb lines each carrying a single Bessel mode with a unique wave num-ber. It might be poten ...

Optica Publishing Group2023

Humidity-insensitive optical fibers for distributed sensing applications

Luc Thévenaz, Tiago Filipe Pimentel Das Neves

Humidity is a critical environmental factor in various applications, and its temperature dependence must be considered when developing thermo-hygrometer fiber sensors. The optical fibers that constitute the sensor must have a temperature reference, which s ...

2023

Improving time-resolution and sensitivity of in situ X-ray photoelectron spectroscopy of a powder catalyst by modulated excitation

Oliver Kröcher, Davide Ferri, Filippo Buttignol

Ambient pressure X-ray photoelectron spectroscopy (APXPS) is a powerful tool to characterize the surface structure of heterogeneous catalysts in situ. In order to improve the time resolution and the signal-to-noise (S/N) ratio of photoemission spectra, we ...

ROYAL SOC CHEMISTRY2023

Hybrid lithium niobate-on-silicon nitride platform for mid-IR supercontinuum generation

Tobias Kippenberg, Mikhail Churaev

Integrated optics has shown itself very convenient for exploiting nonlinear processes as it results in high confinement factor, freedom of dispersion engineering and compactness. However, the choice of materials is crucial for the development of nonlinear ...

SPIE-INT SOC OPTICAL ENGINEERING2023

Scattering from Time-Modulated Transmission-Line Loads: Theory and Experiments in Acoustics

Romain Christophe Rémy Fleury, Matthieu Francis Malléjac

Scattering wave systems that are periodically modulated in time offer many new degrees of freedom to control waves in both the spatial and frequency domains. Such systems, albeit linear, do not conserve frequency and require the adaptation of the usual the ...

American Physical Society (APS)2023

GTC Follow-up Observations of Very Metal-poor Star Candidates from DESI

Pascale Jablonka, Arjun Dey

The observations from the Dark Energy Spectroscopic Instrument (DESI) will significantly increase the numbers of known extremely metal-poor stars by a factor of similar to 10, improving the sample statistics to study the early chemical evolution of the Mil ...

Iop Publishing Ltd2023

Euclid preparation XXVI. The Euclid Morphology Challenge: Towards structural parameters for billions of galaxies

Slobodan Ilic, Georges Meylan, Frédéric Courbin, Richard Massey, Maurizio Martinelli, Gianluca Castignani, Marcello Farina, Yi Wang

The various Euclid imaging surveys will become a reference for studies of galaxy morphology by delivering imaging over an unprecedented area of 15000 square degrees with high spatial resolution. In order to understand the capabilities of measuring morpholo ...

2023

Study on the possibility of Φ-OTDR sensing in hollow-core fibres

Luc Thévenaz, Malak Mohamed Hossameldeen Omar Mohamed Galal, Yuting Yang

The backscattering process in hollow core fibres shows a large similarity with Rayleigh scattering, offering the potential to be exploited for distributed sensing. A classical Φ-OTDR implementation is used to observe the backscattering signal from the surf ...

SPIE2023

Metamaterial graphene photodetector with bandwidth exceeding 500 gigahertz

Michael Baumann, Yesim Koyaz

Although graphene has met many of its initially predicted optoelectronic, thermal, and mechanical properties, photodetectors with large spectral bandwidths and extremely high frequency responses remain outstanding. In this work, we demonstrate a >500 gigah ...

American Association for the Advancement of Science2023

Programmable Silicon Nitride Photonic Integrated Circuits

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

Fluorescence crosstalk reduction by modulated excitation-synchronous acquisition for multispectral analysis in high-throughput droplet microfluidics

Christoph Merten, Jatin Panwar

Crosstalk between fluorescent biomarkers significantly limits the resolution of multispectral fluorescence analysis in real-time droplet-microfluidics applications. The crosstalk is a result of overlapping emission and excitation spectra of different fluor ...

ROYAL SOC CHEMISTRY2023

Nonlinear Integrated Photonics for Ranging Applications

Anton Lukashchuk

This thesis explores the application of recent advances in integrated photonics to the field of light detection and ranging (LiDAR). The progress in photonic integration allows for unprecedented levels of light manipulation on micrometer scales through the ...

EPFL2023

Federated Linear Bandit Learning via Over-the-air Computation

Xin Liu, Ting Wang, Yuning Jiang

In this paper, we investigate federated contextual linear bandit learning within a wireless system that comprises a server and multiple devices. Each device interacts with the environment, selects an action based on the received reward, and sends model upd ...

IEEE2023