Generation of a Bessel beam in FDTD using a cylindrical antenna

TL;DR

This paper presents a novel FDTD method for efficiently generating infinite Bessel beams using a cylindrical antenna, enabling more precise modeling of these beams in optical simulations.

Contribution

The work introduces a new cylindrical antenna injection technique in 3D FDTD for generating Bessel beams, improving computational efficiency and accuracy.

Findings

Successfully generated zeroth and higher-order Bessel beams with various cone angles.

Achieved relative deviations of 0.01-7.0% from analytical solutions.

Reduced computational resources compared to traditional methods.

Abstract

Bessel beams are becoming a very useful tool in many areas of optics and photonics, because of the invariance of their intensity profile over an extended propagation range. Finite-Difference-Time-Domain (FDTD) approach is widely used for the modeling of the beam interaction with nanostructures. However, the generation of the Bessel beam in this approach is a computationally challenging problem. In this work, we report an approach for the generation of the infinite Bessel beams in three-dimensional FDTD. It is based on the injection of the Bessel solutions of Maxwell's equations from a cylindrical hollow annulus. This configuration is compatible with Particle In Cell simulations of laser plasma interactions. This configuration allows using a smaller computation box and is therefore computationally more efficient than the creation of a Bessel-Gauss beam from a wall and models more precisely the analytical infinite Bessel beam. Zeroth and higher-order Bessel beams with different cone angles are successfully produced. We investigate the effects of the injector parameters on the error with respect to the analytical solution. In all cases, the relative deviation is in the range of 0.01-7.0 percent.