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Article
Experimental Demonstration of Coherent Beam Combining Over A 7 km Propagation Path
Optics Letters
  • Thomas Weyrauch, University of Dayton
  • Mikhail Vorontsov, University of Dayton
  • Gary W. Carhart, United States Army Research Laboratory
  • Leonid A. Beresnev, United States Army Research Laboratory
  • Andrey Rostov, Optonicus
  • Ernst Polnau, University of Dayton
  • Jony Jiang Liu, United States Army Research Laboratory
Document Type
Article
Publication Date
11-15-2011
Abstract

We demonstrate coherent combining (phase locking) of seven laser beams emerging from an adaptive fiber- collimator array over a 7km atmospheric propagation path using a target-in-the-loop (TIL) setting. Adaptive control of the piston and the tip and tilt wavefront phase at each fiber-collimator subaperture resulted in automatic focusing of the combined beam onto an unresolved retroreflector target (corner cube) with precompensation of quasi-static and atmospheric turbulence-induced phase aberrations. Both phase locking (piston) and tip–tilt control were performed by maximizing the target-return optical power using iterative stochastic parallel gradient descent (SPGD) techniques. The performance of TIL coherent beam combining and atmospheric mitigation was significantly increased by using an SPGD control variation that accounts for the round-trip propagation delay (delayed SPGD).

Inclusive pages
4455-4457
ISBN/ISSN
0146-9592
Comments

© 2011 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 is on file.

Publisher
Optical Society of America
Peer Reviewed
Yes
Citation Information
Thomas Weyrauch, Mikhail Vorontsov, Gary W. Carhart, Leonid A. Beresnev, et al.. "Experimental Demonstration of Coherent Beam Combining Over A 7 km Propagation Path" Optics Letters Vol. 36 Iss. 22 (2011)
Available at: http://works.bepress.com/mikhail_vorontsov/32/