We present the results from experimental mitigation of wavefront distortions induced by atmospheric turbulence within a 2.4 km near horizontal propagation path using an adaptive optics system based on a model-free optimization strategy. A laser source with a diffuser or a multi-mode fiber-coupled laser were used to model a partially coherent speckle beacon. Propagation path characteristics (intensity scintillations and Strehl ratio fluctuations) were determined for different turbulence conditions. The adaptive optics system comprises a micro-electromechanical mirror and a VLSI controller that implements a stochastic parallel gradient descent (SPGD) algorithm for the optimization process. Experiments performed in an adaptive receiver as well as in an adaptive transceiver configuration demonstrate improvement of the average Strehl ratio even under strong scintillation conditions.

Date Published: 11 December 2003
PDF: 13 pages
Proc. SPIE 5162, Advanced Wavefront Control: Methods, Devices, and Applications, (11 December 2003); doi: 10.1117/12.508080

Published in SPIE Proceedings Vol. 5162:
Advanced Wavefront Control: Methods, Devices, and Applications
John D. Gonglewski; Mikhail A. Vorontsov; Mark T. Gruneisen, Editor(s)