Engineering the axial intensity of Bessel beams

TL;DR

This paper introduces a simple method using two diffractive optical elements to precisely engineer the axial intensity profile of Bessel beams over centimeters-long distances, enhancing their application in laser fabrication.

Contribution

The paper presents a novel technique employing two DOEs to control the axial intensity of Bessel beams without expanding the laser beam, enabling customizable intensity profiles over extended distances.

Findings

Achieved controlled axial intensity profiles over centimeters.

Maintained beam quality without beam expansion.

Demonstrated potential for improved laser fabrication applications.

Abstract

Bessel beams (BBs) appear immune to diffraction over finite propagation distances due to the conical nature of light propagation along the optical axis. This offers promising advantages in laser fabrication. However, BBs exhibit a significant intensity variation along the direction of propagation. We present a simple technique to engineer the axial intensity of the BB over centimeters-long propagation distances without expansion of the incoming laser beam. This method uses two diffractive optical elements (DOEs), one converts the input Gaussian intensity profile to an intermediate intensity distribution, which illuminates the second DOE, a binary axicon. BBs of desired axial intensity distribution over few centimeters length can be fabricated.