Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Concept

Amplification par dérive de fréquence

Publications associées (32)

Numerical Study of the Attosecond Free-Electron Laser Pulse Generation in the Soft X-ray Regime at the SwissFEL

Longdi Zhu

Isolated attosecond pulses from an X-ray free-electron laser are in high demand for attosecond science, which enables the probing of electron dynamics by X-ray nonlinear spectroscopy and single-particle imaging. The aim of this thesis is to simulate attos ...

EPFL2024

Stability of a liquid layer draining around a horizontal cylinder: Interplay of capillary and gravity forces

François Gallaire, Shahab Eghbali, Simeon Vladimirov Djambov

We study the drainage of a viscous liquid film coating the outside of a solid horizontal cylinder, where gravity acts vertically. We focus on the limit of large Ohnesorge numbers Oh, where inertia is negligible compared to viscous effects. We first study t ...

Amer Physical Soc2024

Two statistical regimes in the transition to filamentation

Debbie Eeltink

We experimentally investigate fluctuations in the spectrum of ultrashort laser pulses propagating in air, close to the critical power for filamentation. Increasing the laser peak power broadens the spectrum while the beam approaches the filamentation regim ...

Optica Publishing Group2023

Nanoscale local modification of PMMA refractive index by tip-enhanced femtosecond pulsed laser irradiation

Mihai Adrian Ionescu

Tip-enhanced optical effects have enabled a wide palette of nanoscale investigation techniques and recently they were successfully used to modify and manipulate matter with nanoscale spatial resolution. We contribute to this latter area by reporting a viab ...

ELSEVIER2023

Formation Mechanism of Elemental Te Produced in Tellurite Glass Systems by Femtosecond Laser Irradiation

Yves Bellouard, Gözden Torun

The formation of elemental trigonal tellurium (t-Te) on tellurite glass surfaces exposed to femtosecond laser pulses is discussed. Specifically, the underlying elemental crystallization phenomenon is investigated by altering laser parameters in common tell ...

Wiley2023

Terahertz waveform synthesis in integrated thin-film lithium niobate platform

Ileana-Cristina Benea-Chelmus

Bridging the "terahertz gap" relies upon synthesizing arbitrary waveforms in the terahertz domain enabling applications that require both narrow band sources for sensing and few-cycle drives for classical and quantum objects. However, realization of custom ...

Nature Portfolio2023

Tunable pump compression and fast modulation for pulsed THz generation

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

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

PHz Electronic Device Design and Simulation for Waveguide-Integrated Carrier-Envelope Phase Detection

Yujia Yang

Carrier-envelope phase (CEP) detection of ultrashort optical pulses and low-energy waveform field sampling have recently been demonstrated using direct time-domain methods that exploit optical-field photoemission from plasmonic nanoantennas. These devices ...

IEEE Institute of Electrical and Electronics Engineers2022

Balancing high-speed rotors at low speed using optimized parametric excitation and tuned nonlinear feedback

Amit Yedidia Dolev

The paper presents an improved slow-speed mass balancing procedure capable of reducing high-speed related imbalance. Parametric excitation is used to project the small imbalance forces onto a chosen mode of vibration, corresponding to a high critical rotat ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Single photon detection with amorphous silicon-based microchannel plates: A Monte Carlo model

Christophe Ballif, Nicolas Würsch, Jonathan Emanuel Thomet, Janina Christine Isabelle Löffler, Samira Alexandra Frey

Microchannel plates based on amorphous silicon have the inherent capability to overcome the existing spatial and temporal resolution limitations of single photon detectors. A Monte Carlo model-based study is presented here that serves to exploit their full ...

2022

Ultrafast carrier and quasiparticle dynamics in strongly confined perovskite nanoplatelets

Etienne Christophe Socie

Over the past decade, lead halide perovskites (LHPs) have received considerable attention thanks to their impressive optoelectronic properties. Today, LHP-based devices are one of the most efficient single-junction solar cells, with power-conversion effici ...

EPFL2022

Tunability of space-time wave packet carrying tunable and dynamically changing OAM value

Tobias Kippenberg, Maxim Karpov

Space-time (ST) wave packets have gained much interest due to their dynamic optical properties. Such wave packets can be generated by synthesizing frequency comb lines, each having multiple complex-weighted spatial modes, to carry dynamically changing orbi ...

Optica Publishing Group2022

Ultrashort Pulse Excited Tip-Enhanced Raman Spectroscopy in Molecules

Klaus Kern

Vibrational fingerprints of molecules and lowdimension materials can be traced with subnanometer resolution by performing Tip-enhanced Raman spectroscopy (TERS) in a localization of light in the plasmonic nanocavity of the STM enables high spatial resoluti ...

AMER CHEMICAL SOC2022

Tests and Qualification of the European 1 MW, 170 GHz CW Gyrotron in an ITER relevant configuration at SPC

Timothy Goodman, Stefano Alberti, Jean-Philippe Hogge, Francisco Sanchez, Jérémy Genoud

After an initial testing period at the Karlsruhe Institute of Technology, the upgraded EU 1 MW, 170 GHz continuous wave (CW) industrial prototype gyrotron (TH1509U) for Electron Cyclotron Resonance Heating and Current Drive (ECRH&CD) in ITER has been trans ...

IEEE2022

Highly efficient THz four-wave mixing in doped silicon

Gabriel Aeppli

Third-order non-linearities are important because they allow control over light pulses in ubiquitous high-quality centro-symmetric materials like silicon and silica. Degenerate four-wave mixing provides a direct measure of the third-order non-linear sheet ...

SPRINGERNATURE2021

Photonic chip-based resonant supercontinuum via pulse-driven Kerr microresonator solitons

Tobias Kippenberg, Junqiu Liu, Wenle Weng, Miles Henry Anderson, Tobias Herr, Romain Dany Bruno Bouchand

Supercontinuum generation and soliton microcomb formation both represent key techniques for the formation of coherent, ultrabroad optical frequency combs, enabling the RF-to-optical link. Coherent supercontinuum generation typically relies on ultrashort pu ...

2021

System and method for high beam quality pulse generation in mode-locked multimode fiber lasers

Demetri Psaltis, Christophe Moser, Ugur Tegin

A system and method to generate ultrashort high beam quality pulses from spatio- temporally mode-locked multimode fiber laser are described. The invention relies on engineering the intra-cavity pulse propagation in a multimode laser cavity to shape the spa ...

2021

Vibration monitoring based on optical sensing of mechanical nonlinearities in glass suspended waveguides

Yves Bellouard, Tao Yang, Pieter Vlugter, Enrico Casamenti

Vibration monitoring plays a key role in numerous applications, including machinerypredictive maintenance, shock detection, space applications, packaging-integrity monitoring andmining. Here, we investigate mechanical nonlinearities inherently present in s ...

2021

Ultrafast Photon-Induced Tunneling Microscopy

Klaus Kern

Unification of the techniques of ultrafast science and scanning tunneling microscopy (STM) has the potential of tracking electronic motion in molecules simultaneously in real space and real time. Laser pulses can couple to an STM junction either in the wea ...

AMER CHEMICAL SOC2021

Advanced Progress on chi((3)) Nonlinearity in Chip-Scale Photonic Platforms

Jijun He, Feng Li

chi((3)) nonlinearity enables ultrafast femtosecond scale light-to-light coupling and manipulation of intensity, phase, and frequency. chi((3)) nonlinear functionality in micro- and nanoscale photonic waveguides can potentially replace bulky fiber platform ...

The Electromagnetic Academy2021