Toward defeating diffraction and randomness for laser beam propagation in turbulent atmosphere
P. M. Lushnikov+*, N. Vladimirova*
+Landau Institute for Theoretical Physics, 119334 Moscow, Russia
*Department of Mathematics and Statistics, University of New Mexico, 87131-0001 NM, USA
Abstract
A large distance propagation in turbulent atmosphere
results in disintegration of laser beam into speckles. We find
that the most intense speckle approximately preserves both the Gaussian
shape and the diameter of the initial collimated beam while loosing
energy during propagation.
One per 1000 of atmospheric realizations produces at 7 km distance an
intense speckle above 28 % of the initial power. Such optimal
realizations create effective extended lenses focusing the intense
speckle beyond the diffraction limit of vacuum propagation.
Atmospheric realizations change every several milliseconds. We
propose to use intense speckles to greatly increase the time-averaged
power delivery to the target plane by triggering the pulsed laser operations
only at times of optimal realizations. Resulting power delivery
and laser irradiance at the intense speckles well exceeds both intensity
of diffraction-limited beam and intensity averaged over typical
realizations.