A5060898795- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Cosmology and Gravitation Theories
- High-pressure geophysics and materials
- Laser Material Processing Techniques
- Glass properties and applications
- Laser-induced spectroscopy and plasma
- Advanced Frequency and Time Standards
- Astrophysics and Cosmic Phenomena
- Geophysics and Sensor Technology
- Laser Design and Applications
- Semiconductor materials and devices
- Laser-Matter Interactions and Applications
- Diamond and Carbon-based Materials Research
- Ion-surface interactions and analysis
- Radio Astronomy Observations and Technology
- Cold Atom Physics and Bose-Einstein Condensates
- Metal and Thin Film Mechanics
- Ocular and Laser Science Research
- Atomic and Subatomic Physics Research
- Magnetic confinement fusion research
- Electronic and Structural Properties of Oxides
- Superconducting Materials and Applications
Laboratoire Ville Mobilité Transport
2022-2025
Université Gustave Eiffel
2020-2025
Laboratoire Navier
2020-2025
École nationale des ponts et chaussées
2020-2025
Laboratoire Modélisation et Simulation Multi-Echelle
2023-2025
Université Paris-Est Créteil
2023-2025
Centre National de la Recherche Scientifique
2015-2024
Scuola Internazionale Superiore di Studi Avanzati
2023
University of Nova Gorica
2023
National Research Council
2023
Abstract Blistering is a phenomenon sometimes observed in sputtered-deposited thin films but seldom investigated detail. Here, we consider the case of titania-doped germania (TGO)/silica multilayers deposited by ion beam sputtering. TGO candidate as high refractive index material Bragg mirrors for next iteration gravitational waves detectors. It needs to be annealed at 600 ∘ C 100 h order reach desired relaxation state. However under some growth conditions, 52-layer TGO/silica stacks,...
A Monte Carlo approach was applied for simulations of the early stage (first tens femtosecond) kinetics electronic subsystem silica $({\text{SiO}}_{2})$ in tracks swift heavy ions (SHIs) decelerated stopping regime. At first step multiple ionizations target atoms by a projectile (${\text{Ca}}^{+19}$, $E=11.4\text{ }\text{MeV}/\text{amu}$) were described that gave initial spatial distributions free electrons having different momenta as well holes atomic shells. Spatial propagation fast...
Amorphous SiO2 thin films are one of the two components highly reflective mirror coatings gravitational-wave detectors. For this study, layers amorphous on crystalline Si substrates were produced by ion-beam sputtering (IBS), using accelerated neutralized argon ions as particles, is case for actual The aim study to investigate possible presence various defects in materials order improve coating quality. We provide evidence that, due synthesis method, about 0.2 wt.% Ar present coatings, and...
Amorphous mixed titania-tantala coatings are key components of Bragg reflectors in gravitational-wave detectors (GWDs). Attaining the lowest possible values optical absorption and mechanical losses is paramount importance for GWDs, this requires a complex optimization coating deposition postdeposition annealing. We present here systematic investigation properties internal friction amorphous grown by ion beam sputtering. consider with six different cation mixing ratios─defined as Ti/(Ti +...
We report an experimental and numerical study of femtosecond multipulse laser-induced densification in vitreous silica ($v\ensuremath{-}{\mathrm{SiO}}_{2}$) its signature Raman spectra. compare the findings to recently developed molecular dynamics (MD) approach accounting for bond breaking due laser irradiation, together with a dynamical matrix polarizability model based on first-principles calculations estimation observe two stages spectrum evolution: growth during several hundreds pulses...
Abstract This study explores the impact of crystalline fraction on mechanical losses amorphous tantalum oxide (tantala, Ta 2 O 5 ) thin films intended for gravitational wave detectors. We use ion beam sputtering technique to prepare a series samples, which are then subjected controlled thermal annealing achieve varying degrees crystallized fraction. The microscopic structure annealed samples is characterized by combining different analytical techniques. Our investigation reveals that...
We present a combined study based on the experimental measurements of an infrared (IR) dielectric function and first-principles calculations IR spectra vibrational density states (VDOS) amorphous alumina $(\mathrm{am}\text{\ensuremath{-}}{\mathrm{Al}}_{2}{\mathrm{O}}_{3})$. In particular, we show that main features imaginary part ${\ensuremath{\epsilon}}_{2}(\ensuremath{\omega})$ at $\ensuremath{\sim}380$ 630 ${\mathrm{cm}}^{\ensuremath{-}1}$ are related to motions threefold-coordinated...
We provide a nonperturbative theory for photoionization of transparent solids, which consistently accounts the selection rules related to parity number absorbed photons (odd or even). derive closed-form analytical expressions rate within two-band structure model. Our model exhibits excellent agreement with measurements frequency dependence two-photon absorption and nonlinear refractive index coefficients in sapphire silica, two highly relevant materials industrial applications. demonstrate...
The densification of the vitreous silica (v-SiO2) due to laser irradiation appears reasonable cause change in refractive index. In this letter, v-SiO2 under IR femtosecond is studied within molecular-dynamics simulation. single- and multi-pulse interactions are explored numerically with an account bond-breaking mechanism. By analyzing network at nanoscale, nature assigned reduction major ring fractions six- seven-membered rings minor three- four-membered (related D 2 1 Raman signatures,...
We report a classical molecular-dynamics simulation of models silicon nanoparticles and bulk silicon, in both the crystalline amorphous phase, to investigate their vibrational properties. By using dynamical-matrix approach bond-polarizability model, together with Raman-decomposition [Phys. Rev. B 100, 134309 (2019)], we present comprehensive analysis spectra. In particular, dependence high-frequency range Raman spectra on nanoparticle size is studied. The results are good agreement...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation T. E. Itina, N. Shcheblanov, J.‐Ph. Colombier, R. Stoian, Audouard, Th. Y. Derrien, Torres, J. Hermann, M. Povarnitsyn, K. V. Khishchenko; Laser Applications for Nanotechnology : Insights From Numerical Modeling. AIP Conference Proceedings 8 October 2010; 1278 (1): 38–50. https://doi.org/10.1063/1.3507125...
We present experimental measurements and ab initio simulations of the crystalline amorphous phases ${\mathrm{P}}_{2}{\mathrm{O}}_{5}$. The calculated Raman, infrared, vibrational density states (VDOS) spectra are in excellent agreement with contain signatures all peculiar local structures phase, namely, bridging nonbridging (double-bonded or terminal) oxygens tetrahedral ${\mathrm{PO}}_{4}$ units associated ${Q}^{2}, {Q}^{3}$, ${Q}^{4}$ species (${Q}^{n}$ denotes various types tetrahedra,...
Laser-induced electronic excitation, absorption and relaxation are the key issues in ultra-short laser interactions with dielectric materials. To numerically analyze these processes, a detailed non-equilibrium model is developed based on kinetic Boltzmann equations without any appeal to classical Drude model. The calculations performed including all possible collisional processes. As result, electron energy distributions obtained allowing better analysis of interactions. A remarkable effect...
In this work, optical profilometry and finite-element simulations are applied on buckled micro-machined membranes for the stress analysis of ion-beam-sputtered $\mathrm{Ta_{2}O_{5}}$ $\mathrm{SiO_{2}}$ thin films. Layers with different thicknesses grown silicon substrates, then several geometries manufactured standard micro-system technologies; due to a high level films' compressive stress, obtained. Thermally-grown silica also produced, comparison. The residual values determined by...
The aim of this paper is to clarify details the projectional analysis for atomic vibrations in vitreous silica presented a by Taraskin and Elliott [Phys. Rev. B 56, 8605 (1997)]. description stretching bending modes has been discussed detail while rotational procedure their calculation have not given full detail. We specify method calculating omitted paper. also correct misprint expression ${\mathbf{B}}_{2}^{(E)}$ mode which, unfortunately, reproduced vibrational $E$ some publications.