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Full-Text Articles in Optics
Numerical Investigation Of Statistical Turbulence Effects On Beam Propagation Through 2-D Shear Mixing Layer, James C. Bowers
Numerical Investigation Of Statistical Turbulence Effects On Beam Propagation Through 2-D Shear Mixing Layer, James C. Bowers
Theses and Dissertations
A methodology is developed for determining the validity of making a statistical turbulent approach using Kolmogorov theory to an aero-optical turbulent ow. Kolmogorov theory provides a stochastic method that has a greatly simplified and robust method for calculating atmospheric turbulence effects on optical beam propagation, which could simplify similar approaches to chaotic aero-optical flows. A 2-D laminar Navier-Stokes CFD Solver (AVUS) is run over a splitter plate type geometry to create an aero-optical like shear mixing layer turbulence field. A Matlab algorithm is developed to import the flow data and calculates the structure functions, structure constant, and Fried Parameter ( …
Distributed Beacon Requirements For Branch Point Tolerant Laser Beam Compensation In Extended Atmospheric Turbulence, Virgil E. Zetterlind Iii
Distributed Beacon Requirements For Branch Point Tolerant Laser Beam Compensation In Extended Atmospheric Turbulence, Virgil E. Zetterlind Iii
Theses and Dissertations
Branch point tolerant phase reconstructors can vastly improve adaptive optic system performance in extended atmospheric turbulence. This thesis explores the performance bounds of two such reconstructors Goldstein's algorithm and hidden phase. A least squares reconstructor is implemented for comparison. System performance is presented for various scenarios, including correction time-delays, wave-front sensor noise, and extended beacons. These scenarios are of interest for laser communication and directed energy systems such as Airborne Laser. Performance bounds are obtained through wave-optics simulation. The extended beacon propagation geometry approximates the USAF AFRL-DE North Oscura Peak range. Results show that branch point tolerant reconstructors outperform least …