Effects of Turbulence Instabilities on Laser Propagation

Abstract

Several statistics of the focal spot of a focussed laser beam in turbulent air are computed. The average area is recomputed for horizontal propagation, and corrected graphs are presented. Comparison to the half-power area is made, and it is concluded that the irradiance-weighted radius variance is a slightly better criterion, although the differences are small. The calculations are extended to slant paths. The power spectrum of the area scintillation is shown to be proportional to that of angle of arrival of a ray. It is computed for frozen flow and for random flow with zero mean velocity. Both spectra are initially flat, then decay as f to the minus 2/3 power. A composite formula is suggested for the general case.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1972
Accession Number
AD0744099

Entities

People

  • David A. De Wolf

Organizations

  • Sarnoff Corporation

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Altitude
  • Atmospheric Motion
  • Contracts
  • Data Science
  • Diffraction
  • Focal Planes
  • Frequency
  • Ground Level
  • Information Science
  • Laser Beams
  • Lasers
  • Power Spectra
  • Scintillation
  • Statistics
  • Turbulence
  • Wind
  • Wind Velocity

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Regression Analysis.
  • Space/Atmospheric Physics.

Technology Areas

  • Directed Energy