Generation of a Bessel beam in FDTD using a cylindrical antenna

Ardaneh, Kazem; Giust, Remo; Morel, Benoît; Courvoisier, F.

doi:10.1364/oe.385413

Cited by 11 publications

(9 citation statements)

References 38 publications

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“…The near field fluence distribution of the Bessel beam in vacuum is cylindrically symmetric. 43 This is not the case in our experiments and simulations, as apparent in Figs. 7(b) and 7(c).…”

Section: Near-fieldmentioning

confidence: 51%

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Femtosecond laser-induced sub-wavelength plasma inside dielectrics: I. Field enhancement

Ardaneh,

Meyer,

Hassan

et al. 2022

Preprint

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The creation of high energy density ( 10 6 joules per cm 3 ) over-critical plasmas in a large volume has essential applications in the study of warm dense matter, being present in the hot cores of stars and planets. It was recently shown that femtosecond Bessel beams enable creating over-critical plasmas inside sapphire with subwavelength radius and several tens of micrometers in length. Here, the dependence of field structure and absorption mechanism on the plasma density transverse profile are investigated by performing self-consistent Particle-In-Cell (PIC) simulations. Two limiting cases are considered: one is a homogeneous step-like profile, that can sustain plasmon formation, the second is an inhomogeneous Gaussian profile, where resonance absorption occurs. Comparing experimental absorption measures to analytical predictions allows determining the plasma parameters used in PIC simulations. The PIC simulation results are in good agreement with experimental diagnostics of total absorption, near-field fluence distribution, and far-field radiation pattern. We show that in each case an ambipolar field forms at the plasma surface due to the expansion of the hot electrons and that electron sound waves propagate into the over-critical region.

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Section: Near-fieldmentioning

confidence: 51%

“…We applied a phase φ(r) = −(2π/λ)r sin θ to the Gaussian beam to create a Bessel-Gauss beam. 43 The Bessel beam length for this setup is ≈ 18 µm. The peak intensity in the Bessel zone is 6 × 10 14 W/cm 2 in absence of plasma (pulse energy 1.2 µJ).…”

Section: Simulation Setupsmentioning

confidence: 98%

Femtosecond laser-induced sub-wavelength plasma inside dielectrics: I. Field enhancement

Ardaneh,

Meyer,

Hassan

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…These oscillations in the density power magnitude indicate a redistribution that is able to support the pulsed density power and the pulsed density energy traveling. 1.5x10 13 1.0x10 13 3.0x10 12…”

Section: Resultsmentioning

confidence: 99%

“…In the next sections, by following and enriching some pioneers' works [11][12][13], we detail a fully explicit, stable algorithm based on GVADE FDTD, able to solve the curl Maxwell's equation in a frequency-dependent way for a nonlinear medium. In order to illustrate the combination of all these nonlinear effects occurring simultaneously in a simulation, we have modeled a Bessel beam traveling through dielectric fused silica, where some metal inclusions are modeled in a similar form as in Ref.…”

Section: Introductionmentioning

confidence: 99%

Full Explicit Numerical Modeling in Time-Domain for Nonlinear Electromagnetics Simulations in Ultrafast Laser Nanostructuring

et al. 2021

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The purpose of this paper is to present a new and accurate, fully explicit finite-difference time-domain method for modeling nonlinear electromagnetics. The approach relies on a stable algorithm based on a general vector auxiliary differential equation in order to solve the curl Maxwell’s equation in a frequency-dependent and nonlinear medium. The energy conservation and stability of the presented scheme are theoretically proved. The algorithms presented here can accurately describe laser pulse interaction with metals and nonlinear dielectric media interfaces where Kerr and Raman effects, as well as multiphoton ionization and metal dispersion, occur simultaneously. The approach is finally illustrated by simulating the nonlinear propagation of an ultrafast laser pulse through a dielectric medium transiently turning to inhomogeneous metal-like states by local free-electron plasma formation. This free carrier generation can also be localized in the dielectric region surrounding nanovoids and embedded metallic nanoparticles, and may trigger collective effects depending on the distance between them. The proposed numerical approach can also be applied to deal with full-wave electromagnetic simulations of optical guided systems where nonlinear effects play an important role and cannot be neglected.

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“…We applied a phase φ(r) = −k 0 r sin θ to the Gaussian beam to create a Bessel-Gauss beam. 36 The peak intensity in the Bessel zone is 6 × 10 14 W/cm 2 in the absence of plasma (pulse energy 1.2 µJ). There are 32 particles per cell per species.…”

Section: Pic Simulationsmentioning

confidence: 95%

Femtosecond laser-induced sub-wavelength plasma inside dielectrics. II. Second-harmonic generation

et al. 2022

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Second-harmonic emission at a frequency that is twice the laser frequency is an important diagnostic for nonlinear laser–plasma interaction. It is forbidden for centrosymmetric materials such as the bulk of sapphire. The symmetry, however, can be broken by dielectric discontinuities as a result of plasma generation inside a solid dielectric. In the present work, we explore the basic characteristics of experimentally observed second-harmonic emission during focusing a femtosecond Bessel beam inside sapphire. We employ three-dimensional particle-in-cell simulations and the Helmholtz wave equation for theoretical investigations. We analyze how the efficiency of second-harmonic generation and its polarization depend on the plasma parameters. We find that the second-harmonic is generated either due to the coalescence of two-surface electromagnetic waves or nonlinear interaction between the transverse electromagnetic wave and the longitudinal electron plasma wave driven by linear mode conversion. Experimental results agree with the theoretical predictions and confirm the existence of over-critical plasma inside the sapphire that is essential for the resonance of plasma waves or excitation of surface plasmons.

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Generation of a Bessel beam in FDTD using a cylindrical antenna

Cited by 11 publications

References 38 publications

Femtosecond laser-induced sub-wavelength plasma inside dielectrics: I. Field enhancement

Femtosecond laser-induced sub-wavelength plasma inside dielectrics: I. Field enhancement

Full Explicit Numerical Modeling in Time-Domain for Nonlinear Electromagnetics Simulations in Ultrafast Laser Nanostructuring

Femtosecond laser-induced sub-wavelength plasma inside dielectrics. II. Second-harmonic generation

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