studying the relativistic laser-plasma interaction to avoid complicated mathematical
derivation.
1.5 Relativistic Laser-Plasma Interaction
1.5.1 Relativistic Electron Oscillation
The physics of laser-plasma interaction in relativistic laser intensity is rather new
topics and most of studies have been focused on applications of such laser for
particle accelerations, gamma-ray source, and so on. The physics of laser plasma
coupling and laser absorption has left as still ongoing research. Well-written review
and book are not available yet to understand the basic physics systematically,
although the author referred to two books already published [21]. It is noted that
most of the experimental data have been published in the last decade, and PIC
simulations have been done to analyze the data. The author tries to review
systematically the experimental and simulation result to compare to the theoretical
understanding.
From Chap. 5, the laser-plasma interaction for ultra-short ultra-intense lasers is
explained. When the electron oscillation velocity approaches unity, relativistic effect
such as electron mass increase, strong v  B force, finiteness of laser propagation
velocity, etc. modify the non-relativistic interaction, and new physics such as chaos
or stochastic electron dynamics becomes essential. Brief review of relativistic theory
directly related to the interaction physics is given in Chap. 5. Exact analytic solution
of an electron motion in relativistic laser field is obtained. Using this solution,
nonlinear scatterings of laser by a single electron are studied. Higher harmonic
generation (HHG) is derived in Chap. 5.
The relativistic ponderomotive force in (1.4.7) is clear to become very important
at extremely high intensity. It induces the oscillation of the solid surface with a
period of 10s of femtosecond, before electron expansion to the vacuum makes the
surface blurred. The HHG is observed and can be explained theoretically with the
use of relativistic oscillating mirror (ROM) model. Then, the propagation of
relativistic laser in plasma with density below the cut-off density is studied. In the
relativistic case, the parametric instabilities grow very fast because of the stronger
PM force. The laser spectrum becomes broad, and energy cascade is seen in
frequency space. In the relativistic case, the relativistic mass correction causes
filamentation instability and others. The physics induced by such new nonlinearity
in relativistic regime is studied in Chap. 6.
20
1 Introduction
derivation.
1.5 Relativistic Laser-Plasma Interaction
1.5.1 Relativistic Electron Oscillation
The physics of laser-plasma interaction in relativistic laser intensity is rather new
topics and most of studies have been focused on applications of such laser for
particle accelerations, gamma-ray source, and so on. The physics of laser plasma
coupling and laser absorption has left as still ongoing research. Well-written review
and book are not available yet to understand the basic physics systematically,
although the author referred to two books already published [21]. It is noted that
most of the experimental data have been published in the last decade, and PIC
simulations have been done to analyze the data. The author tries to review
systematically the experimental and simulation result to compare to the theoretical
understanding.
From Chap. 5, the laser-plasma interaction for ultra-short ultra-intense lasers is
explained. When the electron oscillation velocity approaches unity, relativistic effect
such as electron mass increase, strong v  B force, finiteness of laser propagation
velocity, etc. modify the non-relativistic interaction, and new physics such as chaos
or stochastic electron dynamics becomes essential. Brief review of relativistic theory
directly related to the interaction physics is given in Chap. 5. Exact analytic solution
of an electron motion in relativistic laser field is obtained. Using this solution,
nonlinear scatterings of laser by a single electron are studied. Higher harmonic
generation (HHG) is derived in Chap. 5.
The relativistic ponderomotive force in (1.4.7) is clear to become very important
at extremely high intensity. It induces the oscillation of the solid surface with a
period of 10s of femtosecond, before electron expansion to the vacuum makes the
surface blurred. The HHG is observed and can be explained theoretically with the
use of relativistic oscillating mirror (ROM) model. Then, the propagation of
relativistic laser in plasma with density below the cut-off density is studied. In the
relativistic case, the parametric instabilities grow very fast because of the stronger
PM force. The laser spectrum becomes broad, and energy cascade is seen in
frequency space. In the relativistic case, the relativistic mass correction causes
filamentation instability and others. The physics induced by such new nonlinearity
in relativistic regime is studied in Chap. 6.
20
1 Introduction