M.Sc. defense session

Numerical Simulation of Filamentation of Femtosecond Beesel Beams

Mostafa Beigzadeh

Physics Department

Date: 2017-09-21

Time: 10:00

Place: Torkaman Lecture Hall

Abstract: ‎In this thesis‎, ‎filamentation of femtosecond pulses is numerically investigated‎. ‎Also the physics of linear and nonlinear propagation of high-power ultrashort pulses is analyzed and its propagation equation is introduced‎. ‎Since the analytical solution of the nonlinear equation is impossible‎, ‎numerical methods are introduced‎. ‎Of these numerical methods‎, ‎Crank-Nicolson method is chosen and its implementation is described‎. ‎Finally‎, ‎the numerical results for the simulation of the filamentation of a gaussian beam with gaussian pulse are presented and discussed‎. ‎The results of this part are very consistent with the results reported by other groups‎. ‎In addition‎, ‎the results for the simulation of filamentation of femtosecond bessel beams are presented and it is shown that by using the filamentaiton of a combination of bessel beams‎, ‎longitudinal plasma modulation could be made which is promising for various application‎. Keywords‎ : ‎Filamentation‎, ‎Filamanent‎, ‎Bessel beams‎, ‎Kerr effect‎, ‎Plasma‎, ‎Femtosecond pulses‎, ‎ultrashort pulses‎, ‎Crank-Nicolson method‎, ‎Nonlinear optic‎, ‎Longitudinal plasma modulation‎, ‎Multi Photon Absorption (MPA)‎, ‎Multi Photon Ionization (MPI)‎