Abstract

Consideration is given to certain physical phenomena that can attenuate the intensity of a laser beam by refractively spreading or scattering the beam as it propagates. The total attenuation caused by these effects can be well above the usual geometric spreading and absorption losses. Two specific phenomena are analyzed: the nonlinear thermal blooming of the beam (thermal lens effect) and the spreading caused by random variations of the index of refraction of the medium in which the beam is propagating (turbulence effects). The intent of the investigation is to obtain reasonably simple analytic expressions that can be used to estimate or set bounds on the extent of the attenuation. Such expressions are obtained for both the transient and the steady-state effects of thermal blooming when the medium is moving relative to the laser beam, and various estimates are also obtained for the turbulence-induced attenuation of the peak intensity of a beam. For comparison, estimates are also given of the effective attenuation of the beam when it is viewed by a fixed observer, if there are random variations in its direction of propagation.

© 1972 Optical Society of America

Thermal Blooming of Laser Beams in Fluids

John N. Hayes
Appl. Opt. 11(2) 455-461 (1972)

Geometric Optics of Thermal Blooming in Gases. Part 1

P. V. Avizonis, C. B. Hogge, R. R. Butts, and J. R. Kenemuth
Appl. Opt. 11(3) 554-564 (1972)

Turbulence Effects on Thermal Blooming

Frederick G. Gebhardt, David C. Smith, Rudolph G. Buser, and Robert S. Rohde
Appl. Opt. 12(8) 1794-1805 (1973)

Mutual Coherence Function of a Finite Cross Section Optical Beam Propagating in a Turbulent Medium

H. T. Yura
Appl. Opt. 11(6) 1399-1406 (1972)

Laser Beam Propagation Model with a Hydrodynamic Treatment of the Transmission Medium

Warren E. Maher
Appl. Opt. 11(2) 249-256 (1972)