Publications associées à Mode analysis of second-harmonic generation in plasmonic nanostructures

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

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

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

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

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

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

The elliptical Ornstein-Uhlenbeck process

Sofia Charlotta Olhede

We introduce the elliptical Ornstein-Uhlenbeck (OU) process, which is a generalisation of the well-known univariate OU process to bivariate time series. This process maps out elliptical stochastic oscillations over time in the complex plane, which are obse ...

INT PRESS BOSTON, INC2023

Self-sustained dynamics and forced resonant oscillations in flows: cross-junction jets and sloshing liquids

Alessandro Bongarzone

In engineering, oscillatory instabilities and resonances are often considered undesirable flow features and measures are taken to avoid them. This may include avoiding certain parametric regions or implementing control and mitigation strategies. However, t ...

EPFL2023

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

Weak nonlinearity for strong non-normality

François Gallaire, Edouard Boujo, Yves-Marie François Ducimetière

We propose a theoretical approach to derive amplitude equations governing the weakly nonlinear evolution of non-normal dynamical systems, when they experience transient growth or respond to harmonic forcing. This approach reconciles the non-modal nature of ...

Cambridge University Press2022

Quadrature-free immersed isogeometric analysis

Pablo Antolin Sanchez, Thibaut Hirschler

This paper presents a novel method for solving partial differential equations on three-dimensional CAD geometries by means of immersed isogeometric discretizations that do not require quadrature schemes. It relies on a newly developed technique for the eva ...

SPRINGER2022

A Structured Dictionary Perspective on Implicit Neural Representations

Pascal Frossard, Beril Besbinar, Guillermo Ortiz Jimenez, Gizem Yüce

Implicit neural representations (INRs) have recently emerged as a promising alternative to classical discretized representations of signals. Nevertheless, despite their practical success, we still do not understand how INRs represent signals. We propose a ...

IEEE COMPUTER SOC2022

Stabilized isogeometric discretizations on trimmed and union geometries, and weak imposition of the boundary conditions for the Darcy flow

Riccardo Puppi

Modern manufacturing engineering is based on a ``design-through-analysis'' workflow. According to this paradigm, a prototype is first designed with Computer-aided-design (CAD) software and then finalized by simulating its physical behavior, which usually i ...

EPFL2022

Harmonic decomposition of the trace of 1D transfer matrices in layered media

Antonio Joaquin Garcia Suarez

The Transfer Matrix formalism is ubiquitous when it comes to study wave propagation in various stratified media, applications ranging from Seismology to Quantum Mechanics. A relation between variables at two points in two different layers can be establishe ...

2022

Seeded Multimode Quasi-Phase-Matching in All-Optically Poled Silicon Nitride Waveguides

Camille Sophie Brès, Edgars Nitiss, Ozan Yakar

We demonstrate seeding-enabled all-optical poling of silicon nitride waveguides as short as 5 mm, and account for quasi-phase-matching (QPM) inside the waveguide between the fundamental mode of pump and higher order second-harmonic modes. ...

OSA2021

Discovering Tonal Profiles with Latent Dirichlet Allocation

Martin Alois Rohrmeier, Fabian Claude Moss

Music analysis, in particular harmonic analysis, is concerned with the way pitches are organized in pieces of music, and a range of empirical applications have been developed, for example, for chord recognition or key finding. Naturally, these approaches r ...

2021

Doubly resonant second-harmonic generation of a vortex beam from a bound state in the continuum

Jean-François Carlin, Romuald Houdré, Nicolas Grandjean, Matteo Galli, Momchil Minkov, Jun Wang, Marco Clementi

Second-harmonic generation in nonlinear materials can be greatly enhanced by realizing doubly resonant cavities with high quality factors. However, fulfilling such doubly resonant condition in photonic crystal (PhC) slab cavities is a long-standing challen ...

2020

Modes interplay controls the second harmonic generation dynamics of plasmonic nanostructures

Olivier Martin, Gabriel David Bernasconi, Andrei Kiselev

A large amount of experimental and theoretical works deals with the second harmonic generation from different plasmonic geometries. Since they often consider relatively long optical pulses, many of these studies are focused on the investigation of a quasi- ...

SPIE2020

Normalized Gaussian path integrals

Giulio Corazza

Path integrals play a crucial role in describing the dynamics of physical systems subject to classical or quantum noise. In fact, when correctly normalized, they express the probability of transition between two states of the system. In this work, we show ...

AMER PHYSICAL SOC2020

Highly tunable second-harmonic generation in all-optically poled silicon nitride waveguides

Camille Sophie Brès, Anton Stroganov, Edgars Nitiss, Ozan Yakar

The availability of nonlinear parametric processes, such as frequency conversion in photonic integrated circuits is essential. In this contribution, we demonstrate a highly tunable second-harmonic generation in a fully complementary metal–oxide–semiconduct ...

2020

From Polarizability to Effective Permittivity of Time-Varying Materials

Romain Christophe Rémy Fleury, Theodoros Koutserimpas, Mohammad Sajjad Mirmoosa

In this talk, we describe excitation of time-varying dipolar particles (time-modulated meta-atoms) by external time-varying fields from a nonstationary and causal perspective. For a time-harmonic excitation, we introduce a complex-valued function, called t ...

IEEE2020

Dynamics of optical forces and torques in plasmonic systems: a surface integral equation

Olivier Martin, Karim Achouri, Andrei Kiselev

A novel approach is introduced to determine the time evolution of optical forces and torques on arbitrary shape nanostructures by combining Maxwell's stress tensor with the surface integral equation method (SIE). Conventional time averaging of Maxwell’s st ...

SPIEDigitalLibrary2020

Two-Dimensional RBF-ENO Method on Unstructured Grids

Jan Sickmann Hesthaven, Fabian Mönkeberg

Essentially non-oscillatory (ENO) and weighted ENO (WENO) methods on equidistant Cartesian grids are widely used to solve partial differential equations with discontinuous solutions. However, stable ENO/WENO methods on unstructured grids are less well stud ...

SPRINGER/PLENUM PUBLISHERS2020