The filamentation of the laser beam as a labyrinth instability

TL;DR

This paper explores the complex filamentation patterns in high-power laser beams, revealing their similarity to labyrinth instabilities in reaction-diffusion systems and establishing a connection through their underlying dynamical equations.

Contribution

It demonstrates the correlation between laser filamentation patterns and labyrinth instability, linking optical turbulence to activator-inhibitor models through their shared dynamical principles.

Findings

Laser filamentation forms complex, meandering stripe patterns.

Similar spatial structures are observed in reaction-diffusion labyrinth instability.

The underlying equations of both phenomena can be mutually mapped.

Abstract

At incident powers much higher than the threshold for filamentation a pulse from a high-power laser generates in the transversal plane a complex structure. It consists of randomly meandering stripes defining connected regions where the field intensity is high; and, the complementary regions dominated by diffusive plasma with defocusing property. The pattern is similar to an ensemble of clusters of various extensions. We provide evidence that there is a correlation between this filamentation and the {\it labyrinth} instability in reaction-diffusion systems. Besides the similarity of the spatial organization in the two cases, we show that the differential equations that describe these two dynamical processes lead to effects that can be mutually mapped. For the laser beam at high power the Non-linear Schrodinger Equation in a regime of strong self-focusing and ionization of the air leads to multiple filamentation and the structure of clusters. Under the effect of the {\it labyrinth} instability a model of activator-inhibitor leads to a similar pattern. The origin of this connection must be found in the fact that both optical turbulence and the activator-inhibitor dynamics have the nature of competition between two phases of the same system.