Experimental analysis of a laser beam propagating in angular turbulence

Abstract

In this work, a Gaussian laser beam is propagated through a thermally turbulent region before passing through a point diffraction interferometer to produce a circular interferogram. This was done to ascertain how turbulent windstreams of various wind speeds and temperatures affect a laser beam when directed at different angles to the beam axis. The interferometric results portray a clear dependence on the angle of application. That is, deviations away from 90° result in increased wavefront fluctuations. The refractive index structure constant, Rytov variance, and Fried’s parameter were computed to quantify each turbulent model. The attributed strength regimes of these atmospheric parameters were in varying degrees of agreement with the interferometric data. These contradictions and resulting conclusions were discussed in full.

Keywords

• turbulence
• gaussian laser beam
• point diffraction interferometer
• refractive index structure constant
• rytov variance
• fried’s parameter