Measurement of the optical path difference over an atmospheric turbulence phase plate

We report on measurements of optical path differences over a commercially-available phase plate made to simulate atmospheric turbulence. These measurements were made using an AOA mini-Wavescope Shack-Hartmann wavefront sensor consistent with our closed-loop experimental configuration. The atmospheric phase plate, manufactured by Wavefront Sciences Inc., is made to simulate turbulence for five different zenith angles, from overhead to a horizontal path, and five different specified atmospheric coherence lengths. This data will be used as our known, repeatable aberratoin that simulates atmospheric propagation in a closed-loop adaptive optics experiment.