Target-in-the-loop Wavefront Sensing and Control with a Collett–Wolf Beacon: Speckle-average Phase Conjugation

Document Type

Article

Publication Date

1-1-2009

Publication Source

Applied Optics

Abstract

Adaptive optical systems for laser beam projection onto an extended target embedded in an optically inhomogeneous medium are considered. A new adaptive optics wavefront control technique—speckle-average (SA) phase conjugation—is introduced. In this technique mitigation of speckle effects related to laser beam scattering off the rough target surface is achieved by measuring the SA wavefront slopes of the target return wave using a conventional Shack–Hartmann wavefront sensor. For statistically representative speckle averaging we consider the generation of an incoherent light source, referred to here as a Collett–Wolf beacon, directly on the target surface using a rapid steering (scanning) auxiliary laser beam. Our numerical simulations and experiment show that control of the outgoing beam phase using SA phase conjugation can lead to efficient compensation of turbulence effects and results in an increase of the projected laser beam power density on a remote extended target. The impact of both target anisoplanatism and the Collett–Wolf beacon size on adaptive system performance is studied.

Inclusive pages

A13-A29

ISBN/ISSN

1559-128X

Comments

© 2009 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.

Permission documentation on file.

Publisher

Optical Society of America

Volume

48

Issue

1

Peer Reviewed

yes

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