Evaluation of a Concept for Widening the Useful Field-of-View of an Adaptive Optics System

It is well known the useful field-of-view of an adaptive optics system is quite small. For astronomical observation in the visible the size of the isoplanatic patch, θ0, is of the order of 10 μrad. After adaptive optics compensation of turbulence induced wavefront distortion, the mean-square residual wavefront distortion for the imaging of a point source that is an angular distance θ from the direction to the adaptive optics beacon, will have a value of (θ/θ0)5/3 rad2. This suggests that the useful field-of-view is limited by anisoplanatism to a diameter of about 2θ0.