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

2021 ◽  
Vol 11 (16) ◽  
pp. 7429
Author(s):  
Enrique Moreno ◽  
Huu Dat Nguyen ◽  
Razvan Stoian ◽  
Jean-Philippe Colombier
Keyword(s):  
Laser Pulse ◽  
Time Domain ◽  
Metallic Nanoparticles ◽  
Multiphoton Ionization ◽  
Numerical Approach ◽  
Dielectric Medium ◽  
Ultrafast Laser ◽  
Nonlinear Propagation ◽  
Collective Effects ◽  
Stable Algorithm

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.

scholarly journals Reconstruction algorithm for tunneling ionization with a perturbation for the time-domain observation of an electric-field

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wosik Cho ◽  
Jeong-uk Shin ◽  
Kyung Taec Kim
Keyword(s):  
Laser Pulse ◽  
Electric Field ◽  
Time Domain ◽  
Reconstruction Algorithm ◽  
High Order ◽  
Reconstruction Process ◽  
Tunneling Ionization ◽  
Order Contribution ◽  
High Order Contribution ◽  
The Time Domain

AbstractWe present a reconstruction algorithm developed for the temporal characterization method called tunneling ionization with a perturbation for the time-domain observation of an electric field (TIPTOE). The reconstruction algorithm considers the high-order contribution of an additional laser pulse to ionization, enabling the use of an intense additional laser pulse. Therefore, the signal-to-noise ratio of the TIPTOE measurement is improved by at least one order of magnitude compared to the first-order approximation. In addition, the high-order contribution provides additional information regarding the pulse envelope. The reconstruction algorithm was tested with ionization yields obtained by solving the time-dependent Schrödinger equation. The optimal conditions for accurate reconstruction were analyzed. The reconstruction algorithm was also tested using experimental data obtained using few-cycle laser pulses. The reconstructed pulses obtained under different dispersion conditions exhibited good consistency. These results confirm the validity and accuracy of the reconstruction process.

Impact of Nonequilibrium Between Electrons and Phonons on Heat Transfer in Metallic Nanoparticles Suspended in Dielectric Media

2005 ◽  
Vol 127 (12) ◽  
pp. 1400-1402 ◽  
Author(s):  
Y. Sungtaek Ju
Keyword(s):  
Heat Conduction ◽  
Metallic Nanoparticles ◽  
Energy Transport ◽  
Apparent Size ◽  
Dielectric Medium ◽  
Au Nanoparticle ◽  
Conduction Model ◽  
Metallic Structures ◽  
Atomic Vibrations ◽  
Dielectric Interfaces

Controlled heating of nanoparticles is a key enabling technology for various nanomanufacturing and biomedical applications. A theoretical study of energy transport in nanoparticles is conducted to elucidate the role of electron-phonon spatial nonequilibrium in heat conduction across metal-dielectric interfaces. The continuum two-temperature heat conduction model is shown to capture the apparent size dependence of the thermal interface resistance of Au nanoparticle suspensions. Consideration of coupling between electrons and atomic vibrations is important in understanding energy transport in nanoscale metallic structures suspended in a dielectric medium.

scholarly journals Electron and photon beams interacting with plasma

2006 ◽  
Vol 364 (1840) ◽  
pp. 635-645 ◽  
Author(s):  
Albert Reitsma ◽  
Dino Jaroszynski
Keyword(s):  
Laser Pulse ◽  
Electron Bunch ◽  
Laser Pulses ◽  
Plasma Waves ◽  
Intense Laser ◽  
Wave Number ◽  
Collective Effects ◽  
Photon Beams ◽  
Wave Dynamics ◽  
Intense Laser Pulses

A comparison is made between the interaction of electron bunches and intense laser pulses with plasma. The laser pulse is modelled with photon kinetic theory , i.e. a representation of the electromagnetic field in terms of classical quasi-particles with space and wave number coordinates, which enables a direct comparison with the phase space evolution of the electron bunch. Analytical results are presented of the plasma waves excited by a propagating electron bunch or laser pulse, the motion of electrons or photons in these plasma waves and collective effects, which result from the self-consistent coupling of the particle and plasma wave dynamics.

scholarly journals Electron quantum path control in high harmonic generation via chirp variation of strong laser pulses

2021 ◽  
Author(s):  
Stylianos Petrakis ◽  
Makis Bakarezos ◽  
Michael Tatarakis ◽  
Emmanouil Benis ◽  
Nektarios Papadogiannis
Keyword(s):  
Laser Pulse ◽  
Ultraviolet Light ◽  
Harmonic Generation ◽  
Extreme Ultraviolet ◽  
High Harmonic ◽  
High Harmonic Generation ◽  
Ultrafast Laser ◽  
Temporal Window ◽  
Electron Quantum ◽  
Extreme Ultraviolet Light

Abstract The quantum phases of the electron paths driven by an ultrafast laser in high harmonic generation in an atomic gas depends linearly on the instantaneous cycle-averaged laser intensity. Using high laser intensities, a complete single ionisation of the atomic gas may occur before the laser pulse peak. Therefore, high harmonic generation could be localized only in a temporal window at the leading edge of laser pulse envelope. Varying the laser frequency chirp of an intense ultrafast laser pulse, the centre, and the width of the temporal window, that the high harmonic generation phenomenon occurs, could be controlled with high accuracy. This way, both the duration and the phase of the electron trajectories, that generate efficiently high harmonics, is fully controlled. An accurate and robust method of spectral control and selection of the high harmonic extreme ultraviolet light from distinct quantum paths is experimentally demonstrated. Furthermore, a phenomenological numerical model enlightens the physical processes that take place. This novel approach of the electron quantum path selection via laser chirp is a simple and versatile way of controlling the time-spectral characteristics of the coherent extreme ultraviolet light with future applications in the fields of attosecond pulses and soft x-ray nano-imaging.

Multiphoton ionization of atoms by a two-color laser pulse

2011 ◽  
Vol 112 (6) ◽  
pp. 946-951 ◽  
Author(s):  
I. A. Kotelnikov ◽  
A. V. Borodin ◽  
A. P. Shkurinov
Keyword(s):  
Laser Pulse ◽  
Multiphoton Ionization

Fast and direct optical dispersion estimation for ultrafast laser pulse compression

2021 ◽  
Vol 92 (11) ◽  
pp. 113702
Author(s):  
Jui-Chi Chang ◽  
Shu-Yu Chang ◽  
Yu-Cheng Wu ◽  
Chia-Yuan Chang
Keyword(s):  
Laser Pulse ◽  
Pulse Compression ◽  
Ultrafast Laser ◽  
Optical Dispersion ◽  
Ultrafast Laser Pulse

Multiple filaments generation of ultrafast laser pulse by a periodic gas lattice

2021 ◽  
Author(s):  
Yajun Guo ◽  
Jianji Wang ◽  
Xiaowei Song ◽  
Jingquan Lin
Keyword(s):  
Laser Pulse ◽  
Ultrafast Laser ◽  
Ultrafast Laser Pulse

scholarly journals Multiphoton Ionization Mass Spectrometric (MPIMS) Study of Phenol: Mechanism of Ionic Fragment Formation

1983 ◽  
Vol 3 (1-6) ◽  
pp. 29-47 ◽  
Author(s):  
R. S. Pandolfi ◽  
D. A. Gobeli ◽  
Jonathan Lurie ◽  
M. A. El-Sayed
Keyword(s):  
Laser Pulse ◽  
Energy Levels ◽  
Multiphoton Ionization ◽  
Pulsed Laser ◽  
Ionic Species ◽  
Low Energy ◽  
Ionization Mass ◽  
Fragmentation Pattern ◽  
Dissociation Channel ◽  
532 Nm

Time of flight (TOF) mass spectrometry is used in conjunction with a variable repelling voltage technique to elucidate the mechanism by which phenol ionizes and dissociates under 266 nm pulsed laser irradiation in combination with a 532 nm or 355 nm pulsed laser. The results suggest that, like benzene, the molecular ion is the predominant precursor of all ionic species generated in the process. Predominance of C5Hx+ species at relatively low powers confirms the presence of a low energy dissociation channel involving the elimination of CO. The use of a second laser at 532 nm is found to selectively destroy the C5Hx+ (as compared to the parent ion) species. The parent ion is found to be protected from the radiation of the second laser pulse at 532 nm but not at 355 nm if the second laser pulse is delayed by 50 ns. This is explained in terms of relaxation within the parent ion energy levels, the location of a low energy dissociation channel and the wavelengths of the lasers used. The main aspects of the fragmentation pattern are discussed in terms of the statistical theory of Rebentrost and Ben-Shaul.

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