scholarly journals FEMTOSECOND LASER PULSE PROPAGATION IN NOVEL FIBER: TELLURITE GLASS CODOPED ER3+/TM3+

2019 ◽  
Vol 7 (1) ◽  
pp. 96-105
Author(s):  
Khelladi. M
Keyword(s):  
Pulse Propagation ◽  
Tellurite Glass ◽  
Stimulated Raman Scattering ◽  
Nonlinear Effects ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Propagation Equation ◽  
Third Order Dispersion ◽  
Ultrashort Pulse Propagation ◽  
The Impact

In this work we investigated propagation of ultrashort laser pulses in Tellurite glass codoped Er3+/Tm3+. We derived a general propagation equation of pulses which includes the linear and nonlinear effects to all orders. We studied in the specific case of Kerr media and obtained an ultrashort pulse propagation equation called a generalized nonlinear Schrödinger equation. The impact of the third order dispersion, the higher-order nonlinear terms self-steepening, and stimulated Raman scattering are explicitly analyzed.

scholarly journals FDTD Modeling of double ultrashort pulse propagation in nonlinear absorbing media

2020 ◽  
Vol 238 ◽  
pp. 12006
Author(s):  
J.D. Pisonero ◽  
O. Varela ◽  
E. García ◽  
I. Hernández ◽  
J. Ajates ◽  
...  
Keyword(s):  
Finite Difference Time Domain ◽  
Pulse Propagation ◽  
Fdtd Method ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Power Laser ◽  
Ultrashort Pulse Propagation ◽  
Absorbing Media ◽  
Ultrashort Laser ◽  
Difference Time

An approach based on the finite-difference time-domain (FDTD) method is developed for simulating the dynamics of two ultrashort laser pulses inside a saturable absorbing media. This work discusses the results obtained using this numerical model for the prediction of the nonlinear absorbing media behaviour as well as how it affects the final double pulse combination. These results can be used to improve contrast cleaning conditions for high power laser chains and for synchronization studies, this last application was checked in the VEGA facility lab as a code validation.

Numerical Simulation of Ultra-short Laser Pulses Propagation in Gas Media

2020 ◽  
Author(s):  
Katsiaryna Cidorkina ◽  
Alexander Svetashev ◽  
Ilya Bruchkouski ◽  
Siarhei Barodka ◽  
Leonid Turishev
Keyword(s):  
Numerical Simulation ◽  
High Power ◽  
Pulse Propagation ◽  
Stimulated Raman Scattering ◽  
Practical Interest ◽  
Wave Theory ◽  
Laser Pulses ◽  
Pure Nitrogen ◽  
Short Laser Pulses ◽  
Stimulated Raman

<p><span>Over the past ten years, important theoretical and practical results have been obtained in the field of interaction of high-power ultra-short laser pulses with solid transparent media. These results are significant for nonlinear optics and laser physics and are of practical interest for the development of femtosecond laser technology in sensing the environment, in the management of electrical discharge, in microphotonics.</span></p><p><span>However, many of the physical aspects of the supercontinuum generation and distribution of high-power femtosecond and attosecond laser pulses in an optically transparent gas media are not clear and require a detailed theoretical study.</span></p><p><span>Main objectives of the present study are the numerical simulation of high-intensity femtosecond pulses in the air, given the stimulated Raman scattering (SRS) and the stimulated Raman self-mode (SRSM) on pure nitrogen and oxygen molecules as well as on their mixtures.</span></p><p><span>Computer programs have been developed for solving nonlinear equations associated with the SRS and SRSM on the basis of a semi-classical energetic and wave theory with the help of numerical methods. </span></p><p><span>All calculations were made in the Visual Studio C ++ and Java programming environment. </span></p><p><span>The SRS mode for the distance of up to 5m for the main components of the air - nitrogen (78%) and oxygen (21%), in addition to the dynamics of the change of the pulse energy for different initial values have been calculated. </span></p><p><span>The propagation of SRMS laser pulses (λ=400, 800 nm; τ= 14, 20 fs) with positive chirp was numerically investigated for pulse energies 2π, π, π/100 and βz = 0.5, 1.0, 1.5.</span></p><p><span>The results obtained show that the dynamics of pulse propagation in SRMS mode is nonlinear in the pulse shape and spectrum. </span></p><p><span>It was estimated that the calculation results in energetic and wave models for </span>β<span>z≤1.5 are similar.</span></p>

scholarly journals Fokker-Planck simulations of ultrashort-pulse laser-plasma interactions

1992 ◽  
Vol 10 (3) ◽  
pp. 461-471 ◽  
Author(s):  
L. Drska ◽  
J. Limpouch ◽  
R. Liska
Keyword(s):  
Heat Flux ◽  
Distribution Function ◽  
Laser Radiation ◽  
Electric Field ◽  
Electron Distribution ◽  
Electron Distribution Function ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Ultrashort Pulse Laser ◽  
The Impact

The interaction of ultrashort laser pulses with a fully ionized plasma is investigated in the plane geometry by means of numerical simulation. The impact of the space oscillations in the amplitude of the laser electric field on the shape of the electron distribution function, on laser beam absorption, and on electron heat transport is demonstrated. Oscillations in the absorption rate of laser radiation with the minima coincident to the maxima of the laser electric field lead to a further decrease in the absorption of laser radiation. Heat flux in the direction of increasing temperature in the underdense region is caused by the modification of the electron distribution function and by the density gradient. A limitation of heat flux to the overdense plasma isobserved with the flux limiter in range 0.03–0.08, growing moderately with the intensity 1014–1016 W/cm2 of the incident 1.2-ps laser pulse.

scholarly journals Nonlinear Effects with Ultrashort Laser Pulses

2002 ◽  
Vol 101 (1) ◽  
pp. 89-104
Author(s):  
P. Wasylczyk ◽  
W. Wasilewski ◽  
M. Trippenbach ◽  
C. Radzewicz
Keyword(s):  
Nonlinear Effects ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Ultrashort Laser

Modeling of Pulse Propagation Factor Changes in Type II Second Harmonic Generation

2001 ◽  
Vol 6 (2) ◽  
pp. 51-69 ◽  
Author(s):  
A. Kurtinaitis ◽  
A. Dementjev ◽  
F. Ivanauskas
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Pulse Compression ◽  
Pulse Propagation ◽  
Second Harmonic ◽  
Spline Approximation ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Step Method ◽  
High Degree

We describe the simulations of the second harmonic generation of ultrashort laser pulses by numerically solving a system of wave propagation equations. The equations are solved by using a split-step method in twodimensional cyllindrically symmetric space and time coordinates. The diffraction part of a solution uses the Hopscotch type finite-difference scheme on a regular grid. The transport part is solved by using the cubic spline approximation. The obtained numerical results satisfactorily respect energy conservation constraints. The algorithm and program developed make it possible to optimize the process of the second harmonics generation and to identify the conditions where sufficiently high degree of the pulse compression with a relatively low degradation of their quality is achieved.

Influence of gas circulation on stimulated Raman scattering and amplification of ultrashort laser pulses in methane

2008 ◽  
Vol 281 (11) ◽  
pp. 3190-3195 ◽  
Author(s):  
Alexander I. Vodchits ◽  
Valentin A. Orlovich ◽  
Wolfgang Werncke ◽  
Valery P. Kozich
Keyword(s):  
Raman Scattering ◽  
Stimulated Raman Scattering ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Gas Circulation ◽  
Ultrashort Laser ◽  
Stimulated Raman

scholarly journals Effect of longitudinal epsilon-near-zero regime in dynamics of ultrashort laser pulses in hyperbolic metamaterials

2021 ◽  
Vol 2015 (1) ◽  
pp. 012098
Author(s):  
Vladimir Novikov
Keyword(s):  
Pulse Propagation ◽  
Field Enhancement ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Pulse Delay ◽  
Hyperbolic Metamaterials ◽  
Spectral Point ◽  
Slow Pulse ◽  
Ultrashort Laser ◽  
Epsilon Near Zero

Abstract Optical properties of hyperbolic metamaterials (HMMs) are in stark contrast to properties of ordinary media that fuels interest to various applications of HMMs in photonics. Special attention is attributed to the epsilon-near zero regime (ENZ) of HMMs that is the spectral point in which real part of the permittivity of the HMM becomes zero. This is accompanied by the effects of field enhancement having far-reaching applications. Here we focus on the experimental and theoretical investigation of the propagation of an ultrashort laser pulse through the silver nanorod-based HMM slab in the spectral range over the ENZ. We revealed pronounced resonant change of the pulse delay in HMMs and the transition between the superluminal and slow pulse propagation at the ENZ spectral point. Observed dynamical phenomena are confirmed theoretically and attributed to unusual case when the spectral half of an ultrashort pulse has elliptical dispersion and another has the hyperbolic one. Special attention is payed to the propagation of chirped laser pulses in the HMMs.

scholarly journals Understanding Nonlinear Pulse Propagation in Liquid Strand-Based Photonic Bandgap Fibers

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 305
Author(s):  
Xue Qi ◽  
Kay Schaarschmidt ◽  
Guangrui Li ◽  
Saher Junaid ◽  
Ramona Scheibinger ◽  
...  
Keyword(s):  
Frequency Conversion ◽  
Pulse Propagation ◽  
Photonic Bandgap ◽  
Supercontinuum Generation ◽  
Nonlinear Frequency ◽  
Dispersive Wave ◽  
Nonlinear Frequency Conversion ◽  
Photonic Bandgap Fiber ◽  
Third Order Dispersion ◽  
The Impact

Ultrafast supercontinuum generation crucially depends on the dispersive properties of the underlying waveguide. This strong dependency allows for tailoring nonlinear frequency conversion and is particularly relevant in the context of waveguides that include geometry-induced resonances. Here, we experimentally uncovered the impact of the relative spectral distance between the pump and the bandgap edge on the supercontinuum generation and in particular on the dispersive wave formation on the example of a liquid strand-based photonic bandgap fiber. In contrast to its air-hole-based counterpart, a bandgap fiber shows a dispersion landscape that varies greatly with wavelength. Particularly due to the strong dispersion variation close to the bandgap edges, nanometer adjustments of the pump wavelength result in a dramatic change of the dispersive wave generation (wavelength and threshold). Phase-matching considerations confirm these observations, additionally revealing the relevance of third order dispersion for interband energy transfer. The present study provides additional insights into the nonlinear frequency conversion of resonance-enhanced waveguide systems which will be relevant for both understanding nonlinear processes as well as for tailoring the spectral output of nonlinear fiber sources.

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