Publications associées à High harmonic generation

Nonlinear optical diode effect in a magnetic Weyl semimetal

Philip Johannes Walter Moll, Chunyu Guo, Hao Yang

Diode effects are of great interest for both fundamental physics and modern technologies. Electrical diode effects (nonreciprocal transport) have been observed in Weyl systems. Optical diode effects arising from the Weyl fermions have been theoretically co ...

Nature Portfolio2024

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

High-order geometric integrators for the variational Gaussian wavepacket dynamics and application to vibronic spectra at finite temperature

Roya Moghaddasi Fereidani

Molecular quantum dynamics simulations are essential for understanding many fundamental phenomena in physics and chemistry. They often require solving the time-dependent Schrödinger equation for molecular nuclei, which is challenging even for medium-sized ...

EPFL2024

Tunable photo-induced second-harmonic generation in a mode-engineered silicon nitride microresonator

Camille Sophie Brès, Jianqi Hu, Anton Stroganov, Boris Zabelich, Edgars Nitiss

All-optical poling enables reconfigurable and efficient quasi-phase-matching for second-order parametric frequency conversion in silicon nitride integrated photonics. Here, we report broadly tunable milliwatt-level second-harmonic generation in a small fre ...

2023

Progress and prospects in nonlinear extreme-ultraviolet and X-ray optics and spectroscopy

Majed Chergui

Free-electron lasers and high-harmonic-generation table-top systems are new sources of extreme-ultraviolet to hard X-ray photons, providing ultrashort pulses that are intense, coherent and tunable. They are enabling a broad range of nonlinear optical and s ...

NATURE PORTFOLIO2023

Dissipative phase transitions in n-photon driven quantum nonlinear resonators

Vincenzo Savona, Fabrizio Minganti

We investigate and characterize the emergence of finite-component dissipative phase transitions (DPTs) in nonlinear photon resonators subject to n-photon driving and dissipation. Exploiting a semiclassical approach, we derive general results on the occurre ...

Verein Forderung Open Access Publizierens Quantenwissenschaf2023

Nonlinear Frequency Conversion in III-Nitride Doubly Resonant Photonic Crystal Cavities

Jun Wang

Nonlinear frequency conversion processes, such as second-harmonic generation (SHG) and spontaneous parametric down-conversion (SPDC), are essential in many applications, including the generation of entangled photons. It's desirable to enhance these process ...

EPFL2023

In situ monitoring of femtosecond laser-induced modifications in dielectrics

Olivier Bernard

Over the last decades, the progress made in the generation of laser pulses shorter than a picosecond (10^-12 s) has allowed us to reach extreme optical power intensities exceeding 10^15 W cm^-2. This tremendous power has triggered an abundance of original ...

EPFL2023

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

A chip-scale second-harmonic source via self-injection-locked all-optical poling

Tobias Kippenberg, Camille Sophie Brès, Junqiu Liu, Edgars Nitiss, Marco Clementi

Second-harmonic generation allows for coherently bridging distant regions of the optical spectrum, with applications ranging from laser technology to self-referencing of frequency combs. However, accessing the nonlinear response of a medium typically requi ...

2023

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

Broadband Air-Coupled Ultrasound Emitter and Receiver Enable Simultaneous Measurement of Thickness and Speed of Sound in Solids

Janez Rus

Air-coupled ultrasound sensors have advantages over contact ultrasound sensors when a sample should not become contaminated or influenced by the couplant or the measurement has to be a fast and automated inline process. Thereby, air-coupled transducers mus ...

MDPI2023

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

Critical Schrodinger Cat Qubit

Vincenzo Savona, Fabrizio Minganti, Luca Gravina

Encoding quantum information onto bosonic systems is a promising route to quantum error correc-tion. In a cat code, this encoding relies on the confinement of the dynamics of the system onto the two-dimensional manifold spanned by Schrodinger cats of oppos ...

AMER PHYSICAL SOC2023

A weakly nonlinear amplitude equation approach to the bypass transition in the two-dimensional Lamb–Oseen vortex

François Gallaire, Yves-Marie François Ducimetière

We analytically derive an amplitude equation for the weakly nonlinear evolution of the linearly most amplified response of a non-normal dynamical system. The development generalizes the method proposed in Ducimetière et al. (J. Fluid Mech., vol. 947, 2022, ...

Cambridge University Press2023

Generalized Coherent Photogalvanic Effect in Coherently Seeded Waveguides

Camille Sophie Brès, Jianqi Hu, Ozan Yakar, Edgars Nitiss

The coherent photogalvanic effect leads to the generation of a current under the absorption interference of coherent beams and allows for the inscription of space-charge gratings leading to a second-order susceptibility (chi((2))). The inscribed grating au ...

2022

Optically reconfigurable quasi-phase-matching in silicon nitride microresonators

Camille Sophie Brès, Jianqi Hu, Anton Stroganov, Edgars Nitiss

Quasi-phase-matching has long been a widely used approach in nonlinear photonics, enabling efficient parametric frequency conversions such as second-harmonic generation. However, in silicon photonics the task remains challenging, as materials best suited f ...

Nature Publishing Group2022

Gd3+-Functionalized Lithium Niobate Nanoparticles for Dual Multiphoton and Magnetic Resonance Bioimaging

Marinella Mazzanti, Sandrine Gerber, Anne-Sophie Chauvin, Katarzyna Pierzchala, Ileana Ozana Jelescu, Jérémy Vuilleumier, Raphaël Jovita De Matos, Laura Camille Louise Nicolle, Adrian Stefan Gheata, Dario Diviani, Luigi Bonacina, Fiorella Lucarini

Harmonic nanoparticles (HNPs) have emerged as appealing exogenous probes for optical bioimaging due to their distinctive features such as long-term photostability and spectral flexibility, allowing multiphoton excitation in the classical (NIR-I) and extend ...

2022

Electric-field poling of silicon nitride waveguides for the linear phase modulation

Camille Sophie Brès, Anton Stroganov, Boris Zabelich, Edgars Nitiss

Stoichiometric silicon nitride (Si3N4) constitutes a mature platform for integrated photonics. Its pertinent properties, including wide transparency window from the visible to the mid-IR, low propagation loss, and high third-order nonlinearity, are exploit ...

SPIE-INT SOC OPTICAL ENGINEERING2022

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