Laboratory phase plate turbulence strength characterization

The production of atmospheric-like turbulence is important to evaluate adaptive optics performance. Several techniques are commonly used to produce atmospheric-like turbulence in the laboratory, such as heating airflow, using diffractive and refractive optical components, and the atmospheric turbulence phase plate; however, the atmospheric turbulence phase plate has the advantage of low cost and easy control of the turbulence property. The properties of phase plates have been studied by many authors; however, a practical methodology to characterize the turbulence strength of the phase plate has not been discussed. The purpose of this paper is to propose a practical methodology to characterize the turbulence strength of the phase plate. In order to develop the methodology, a theoretical model of the optical system with the phase plate is derived first and the turbulence strength metric, which is in terms of the incident beam size versus D/r0, is obtained based on a comparison of theoretical and experimental data.