Strong Turbulence Effects on Short Wavelength Lasers.
Abstract
The mean square wander angle of a focused laser beam transmitted through a homogeneous-isotropic turbulent medium has been determined by the use of the extended Huygens-Fresnel principle. The theory is developed for both weak and strong turbulence conditions for which the electromagnetic field statistics are known. A heuristic formula for the wander angle is developed which connects the turbulence regimes. Although the theory is general, numerical results are determined for uniformly illuminated laser aperture only. The mean square angle of arrival of a spherical wave source in the laser focal plane and detected in the laser aperture plane is also determined. The correlation function of the angle of arrival, determined by means of the centroid, and the angle of arrival, determined by means of a least squares fit of the received phase over the aperture, is discussed. It is shown that this correlation is nearly 100% in the regime of weak turbulence conditions. Finally, engineering formulas useful for hand calculation of wander angle and peak on-axis transmitted intensity in the focal plane of a tilt corrected laser beam are presented. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 15, 1979
- Accession Number
- ADA079748
Entities
People
- Hal T. Yura
- Michael T. Tavis
Organizations
- The Aerospace Corporation