The propagation dynamics and stability of an intense laser beam in a radial power-law plasma channel

Abstract

By containing ponderomotive self-channeling, the propagation behavior of an intense laser beam and the physical conditions are obtained theoretically in a radial power-law plasma channel. It is found that ponderomotive self-channeling results in the emergence of a solitary wave and catastrophic focusing, which apparently decreases the region for stable propagation in a parameter space of laser power and the ratio of the initial laser spot radius to the channel radius (RLC). Direct numerical simulation confirms the theory of constant propagation, periodic defocusing and focusing oscillations in the parameter space, and reveals a radial instability which prevents the formation of bright and dark solitary waves. The corresponding unstable critical curve is added in the parameter space numerically and the induced unstable region above the unstable critical curve covers that of catastrophic focusing, which shrinks the stable region for laser beams. For the expected constant propagation, the results reveal the need for a low RLC. Further study illustrates that the channel power-law exponent has an obvious effect on the final stable region and laser propagation, for example increasing this exponent can enlarge the stable region significantly, which is beneficial for guiding of the laser and increases the lowest RLC for constant propagation. Our results also show that the initial laser amplitude has an apparent influence on the propagation behavior.

Stabilization and correction of aberrated laser beams via plasma channelling.

“…Various methods are possible to generate and shape a plasma channel 20,21 , making their practical application possible and thus their studies interesting. Former research demonstrated, using 2D PIC simulations, that a Gaussian beam can be well guided inside a parabolic plasma channel, and that distortions can be reduced compared to a non-parabolic plasma channel 22 , while the importance of the function that defines the plasma channel has been evidenced 23 . In this article, we propose to use a method that enables us to confidently propagate any aberrated laser beams inside a plasma channel, hence proving that even distorted beams can be converted into a single plasma mode.…”

Stabilization and correction of aberrated laser beams via plasma channelling

“…Various methods are possible to generate and shape a plasma channel 20 , 21 , making their practical application possible and thus their studies interesting. Former research demonstrated, using 2D PIC simulations, that a Gaussian beam can be well guided inside a parabolic plasma channel, and that distortions can be reduced compared to a non-parabolic plasma channel 22 , while the importance of the function that defines the plasma channel has been evidenced 23 .…”