Propagation of High Energy Laser Beams Through Atmospheric Stagnation Zones

Abstract

Stagnation zones, i.e., regions in which the effective wind velocity is zero, can greatly enhance the thermal blooming of high-energy laser (HEL) beams in the atmosphere. An expression for the Strehl ratio of a focused HEL beam propagating through a stagnant absorbing region is derived. The propagation of a HEL beam in a maritime atmosphere is numerically modeled in a fully three-dimensional and time-dependent manner. The beam is focused onto a remote target, and a stagnation zone is created by slewing the laser in the direction of the wind. The laser power delivered to the target is calculated as a function of slew rate. For the parameters considered, it is found that a stagnation zone near the laser source has little effect on the propagation efficiency while a stagnation zone near the target can significantly reduce the power on the target.

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Document Details

Document Type
Technical Report
Publication Date
Jan 27, 2006
Accession Number
ADA444656

Entities

People

  • Bahman Hafizi
  • Joseph R. PeƱano
  • Phillip A. Sprangle

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • C4I
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Absorption Coefficients
  • Atmospheres
  • Atmospheric Motion
  • Blooming
  • Coefficients
  • Energy
  • Geometry
  • High Energy
  • High Energy Lasers
  • Laser Beams
  • Laser Spots
  • Scattering
  • Strehl Ratio
  • Thermal Blooming
  • Three Dimensional
  • Wind
  • Wind Velocity

Fields of Study

  • Physics

Readers

  • Fluid Dynamics.
  • Optical Physics and Photonics.
  • Pulsed Power and Plasma Physics.

Technology Areas

  • Directed Energy