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Optimization of wavefront-sensorless adaptive optics for horizontal laser beam propagation in a realistic turbulence environment

 
: Segel, Max; Zepp, Andreas; Anzuola, Esdras; Gladysz, Szymon; Stein, Karin

:

Bos, J.P. ; Society of Photo-Optical Instrumentation Engineers -SPIE-, Bellingham/Wash.:
Laser Communication and Propagation through the Atmosphere and Oceans VI : 8-9 August 2017, San Diego, California, United States
Bellingham, WA: SPIE, 2017 (Proceedings of SPIE 10408)
ISBN: 978-1-5106-1273-0
ISBN: 978-1-5106-1274-7
Paper 104080E, 8 pp.
Conference "Laser Communication and Propagation through the Atmosphere and Oceans" <6, 2017, San Diego/Calif.>
English
Conference Paper
Fraunhofer IOSB ()
adaptive optic; SPGD; dynamic turbulence; Zernike modes; Karhunen-Loeve polynomials

Abstract
Unconventional wavefront sensing strategies are being developed to provide alternatives for measuring the wavefront deformation of a laser beam propagating through strong turbulence and/or along a horizontal path. In this paper we present a modified wavefront-sensorless (WFS) adaptive optical (AO) system where the well-known stochastic parallel gradient descent (SPGD) algorithm is extended with a-priori knowledge of the spatial and temporal statistics related to atmospheric turbulence. Here, a modal implementation of the correction algorithm allows us to exploit modal wavefront decomposition to decrease SPGD optimization complexity. We also propose an implementation of a modal decomposition based on Karhunen-Lo´eve polynomials instead of the common Zernike polynomials. Appropriate calibration of the deformable mirror is also presented. Performance evaluation of this modified wavefront-sensorless AO system is carried out in a realistic simulated turbulence environment and the results are compared against the traditional, zonal SPGD algorithms.

: http://publica.fraunhofer.de/documents/N-473533.html