Influence of an Atmospheric Turbulence Simulator on the Parameters of a Bessel Light Beam with Different Configurations of an Optical Setup

Abstract

The influence of a medium containing optical inhomogeneities on Bessel light beam (BLB) parameters has been comprehensively studied. BLBs were formed by an optical setup in two configurations. Configuration I had a Gaussian (or Laguerre-Gaussian) laser beam propagating through an atmospheric turbulence simulator (ATS). The resulting distorted beam was then used to form a zero- (first-) order BLB with the help of an axicon. A zero-order BLB was formed for an incident Gaussian beam; a first-order BLB, for a Laguerre-Gaussian beam. Configuration II had zero- and first-order BLBs formed from a Gaussian (Laguerre-Gaussian) light beam propagating at once through the ATS. Correspondingly, the original Gaussian and Laguerre-Gaussian beams were undisturbed in this case. The presence of inner-scale turbulence less than the diameter of the laser beam propagating through it significantly changed the BLB quality parameters in both configurations. The most sensitive parameter was the constancy; the least sensitive, the roundness. The sensitivity of all quality parameters increased with increasing distance from the axicon. The beam-axis location reacted well to large scale inhomogeneities significantly larger than the diameter of the beam propagating through the ATS. Because a zero-order BLB was much more easily formed than a first-order BLB, it was optimal to use a zero-order BLB to investigate the turbulence. It was rational to use configuration I with a Gaussian beam passing through the ATS for unambiguity and a clear interpretation of the results. The results could be used for the development of analyzers (detectors) of heterogeneity in a liquid or gaseous medium under natural conditions and in industry and for quality assessment of extended transparent products.