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Engineering Physics

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Air Force Institute of Technology

Coherence (optics)

Publication Year

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Full-Text Articles in Physics

M2 Factor Of A Vector Schell-Model Beam, Milo W. Hyde Iv, Mark F. Spencer Jan 2019

M2 Factor Of A Vector Schell-Model Beam, Milo W. Hyde Iv, Mark F. Spencer

Faculty Publications

Extending existing scalar Schell-model source work, we derive the M2 factor for a general electromagnetic or vector Schell-model source to assess beam quality. In particular, we compute the M2 factors for two vector Schell-model sources found in the literature. We then describe how to synthesize vector Schell-model beams in terms of specified, desired M2 and present Monte Carlo simulation results to validate our analysis.


Estimation Of Turbulence From Time-Lapse Imagery, Jack E. Mccrae, Santasri Bose-Pillai, Steven T. Fiorino Feb 2017

Estimation Of Turbulence From Time-Lapse Imagery, Jack E. Mccrae, Santasri Bose-Pillai, Steven T. Fiorino

Faculty Publications

Atmospheric turbulence parameters are estimated for an imaging path based on time-lapse imaging results. Atmospheric turbulence causes frame-to-frame shifts of the entire image as well as parts of the image. The statistics of these shifts encode information about the turbulence strength (as characterized by Cn2, the refractive index structure function constant) along the optical path. The shift variance observed is simply proportional to the variance of the tilt of the optical field averaged over the area being tracked and averaged over the camera aperture. By presuming this turbulence follows the Kolmogorov spectrum, weighting functions, which relate the turbulence strength along …