Share Email Print

Proceedings Paper

Experimental Measurements Of Turbulence Induced Beam Spread And Wander At 1.06, 3.8, And 10.6 µm
Author(s): D. M. Cordray; S. K. Searles; S. T. Hanley; J. A. Dowling; C. O. Gott
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

Lasers can be used for a number of applications involving atmospheric propagation. In these applications it is of interest to know the maximum range at which the laser beam can propagate without significant degradation due to atmospheric turbulence. The purpose of the measurements was to determine laser beam spread and wander as a function of the infrared wavelength, the optical turbulence level, and the propagation distance. Experiments were performed at White Sands Missile Range under conditions of low over-land turbulence levels, using 1.06μm, 3.8007μm, and 10.591μm lasers at ranges of 2, 6.4, and 10.5 km. The tests were conducted under a range of turbulence conditions, with CN2 most frequently of the order of 10-15 m-2/3. The NRL Infrared Mobile Optical Radiation Laboratory (IMORL) was used to generate the nearly diffraction limited beams produced by the lasers, to magnify the beam to a 90 cm diameter and to focus the beams onto a 120 cm collector. The intensity distribution at the collector mirror was recorded by a scanning infrared camera which dissects the image into 810 elements. The intensity distributions were recorded at a scan rate of up to 500 frames per second. Two dimensional scanning at the high scan rates provided excellent spatial and temporal resolution of the turbulence-degraded focal spot distributions. The data has been partially reduced and shows that 1.06μm is severly spread and broken up, that 3.8μm is slightly spread, and that 10.6μm shows little spread relative to its diffraction limited spot size.

Paper Details

Date Published: 30 December 1981
PDF: 8 pages
Proc. SPIE 0305, Atmospheric Effects on Electro-Optical, Infrared, and Millimeter Wave Systems Performance, (30 December 1981); doi: 10.1117/12.932741
Show Author Affiliations
D. M. Cordray, Naval Research Laboratory (United States)
S. K. Searles, Naval Research Laboratory (United States)
S. T. Hanley, Naval Research Laboratory (United States)
J. A. Dowling, Naval Research Laboratory (United States)
C. O. Gott, Naval Research Laboratory (United States)

Published in SPIE Proceedings Vol. 0305:
Atmospheric Effects on Electro-Optical, Infrared, and Millimeter Wave Systems Performance
Richard Gomez, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?