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Full-Text Articles in Physical Sciences and Mathematics
The Behavior Of Partially Coherent Twisted Space-Time Beams In Atmospheric Turbulence, Milo W. Hyde Iv
The Behavior Of Partially Coherent Twisted Space-Time Beams In Atmospheric Turbulence, Milo W. Hyde Iv
Faculty Publications
We study how atmospheric turbulence affects twisted space-time beams, which are non-stationary random optical fields whose space and time dimensions are coupled with a stochastic twist. Applying the extended Huygens–Fresnel principle, we derive the mutual coherence function of a twisted space-time beam after propagating a distance z through atmospheric turbulence of arbitrary strength. We specialize the result to derive the ensemble-averaged irradiance and discuss how turbulence affects the beam’s spatial size, pulse width, and space-time twist. Lastly, we generate, in simulation, twisted space-time beam field realizations and propagate them through atmospheric phase screens to validate our analysis.
Profiling Atmospheric Turbulence Using A Dynamically Ranged Rayleigh Beacon System, Steven M. Zuraski
Profiling Atmospheric Turbulence Using A Dynamically Ranged Rayleigh Beacon System, Steven M. Zuraski
Theses and Dissertations
The effect of turbulence on a long range imaging system manifest as an image blur effect usually quantified by the phase distortions present in a system. The blurring effect is conceivably understood on the basis of measured strength of atmospheric turbulence profiled within the propagation volume. One method for obtaining a turbulence strength profile is by use of a dynamically ranged Rayleigh beacon system that exploits strategically varied beacon ranges along the propagation path, effectively deducing estimates of specific path segment contributions of the blurring aberrations affecting an optical imaging system. A system utilizing this technique has been designed, and …
Turbulence Profiling Using Pupil Plane Wavefront Data Derived Fried Parameter Values For A Dynamically Ranged Rayleigh Beacon, Steven M. Zuraski, Elizabeth Beecher, Jack E. Mccrae, Steven T. Fiorino
Turbulence Profiling Using Pupil Plane Wavefront Data Derived Fried Parameter Values For A Dynamically Ranged Rayleigh Beacon, Steven M. Zuraski, Elizabeth Beecher, Jack E. Mccrae, Steven T. Fiorino
Faculty Publications
Long-range optical imaging applications are typically hindered by atmospheric turbulence. The effect of turbulence on an imaging system can manifest itself as an image blur effect usually quantified by the phase distortions present in the system. The blurring effect can be understood on the basis of the measured strength of atmospheric optical turbulence along the propagation path and its impacts on phase perturbation statistics within the imaging system. One method for obtaining these measurements is by the use of a dynamically ranged Rayleigh beacon system that exploits strategically varied beacon ranges along the propagation path, effectively obtaining estimates of the …
Measurements Of Optical Turbulence Over 149-Km Path, Jack E. Mccrae, Santasri Bose-Pillai, Steven T. Fiorino, Aaron J. Archibald, Joel Meoak, Brannon Elmore, Thomas Kesler, Christopher A. Rice
Measurements Of Optical Turbulence Over 149-Km Path, Jack E. Mccrae, Santasri Bose-Pillai, Steven T. Fiorino, Aaron J. Archibald, Joel Meoak, Brannon Elmore, Thomas Kesler, Christopher A. Rice
Faculty Publications
An experiment was conducted to study turbulence along a 149-km path between the Mauna Loa and Haleakala mountain tops using digital cameras and light-emitting diode (LED) beacons. Much of the path is over the ocean, and a large portion of the path is 3 km above sea level. On the Mauna Loa side, six LED beacons were placed in a roughly linear array with pair spacings from 7 to 62 m. From the Haleakala side, a pair of cameras separated by 83.8 cm observed these beacons. Turbulence along the path induces tilts on the wavefronts, which results in displacements of …
Realistic Vertical Atmospheric Profiles And Effects From Limited Surface Observations, Dane P. Ranney
Realistic Vertical Atmospheric Profiles And Effects From Limited Surface Observations, Dane P. Ranney
Theses and Dissertations
The ability to accurately describe the atmospheric conditions around us is not only important to the Air Force, but to anyone involved in signal propagation. The programs currently utilized to describe the atmosphere take into account a variety of measures. The LEEDR (Laser Environmental Effects Definition and Reference) program in particular, allows the user to select a location, aerosol and molecular effects model, numerous cloud and precipitation events, as well as other features. Even with the control that the user has, the output that the program provides can vary from actual conditions on a day to day basis. This is …
Atmospheric Turbulence Scintillation Effects On Wavefront Tilt Estimation, James A. Louthain
Atmospheric Turbulence Scintillation Effects On Wavefront Tilt Estimation, James A. Louthain
Theses and Dissertations
A new atmospheric turbulence screen generator is developed for use in performance calculations of adaptive optics systems valid over a wide range of atmospheric turbulence parameters. The screen generator accounts for diffraction effects caused by weak turbulence and incorporates the phase, amplitude, and cross statistics of the perturbed optical field. The wavefront's phase and amplitude perturbations are taken from the correlation functions developed by Lee and Harp and the cross correlation of the phase and amplitude derived in this thesis. The screen generator uses a modal representation to perform a Fourier series expansion of the wavefront phase and amplitude over …