Generation of bottle beam using low-density channel in air

TL;DR

This paper numerically investigates how femtosecond laser pulses create low-density channels in air, revealing a new method to generate bottle beams by controlling the density depression in the gas.

Contribution

It introduces a novel approach to generate bottle beams using low-density channels formed by femtosecond laser filamentation in air.

Findings

Density holes become shallower and wider with higher temperature elevations.

Simulation shows potential for new bottle beam generation method.

Density profile evolution depends on energy deposition and temperature.

Abstract

Cylindrical density depressions generated by femtosecond laser pulses filamenting in air for different energy depositions is investigated numerically, by using a set of hydrodynamic equations. The evolution of density profile is calculated for different temperature elevations, the results indicate that the gas density hole is getting shallower and wider with the increasing temperature elevations. A simulation of the propagation inside low-density channel implies a new way to generate a type of bottle beam.