Scintillation Resistant Wave-Front Sensors for Strong-Turbulence Adaptive Optics

Wavefront sensing in high scintillation environments is degraded in conventional sensors by a coupling, in the measurement, between phase and irradiance variations. An evaluation of this effect, and its impact on performance of systems, such as ABL, isproposed. An innovative wavefront sensor design has been proposed which mitigates this effect by pixel-level processing of the data. The design exhibits other advantageous features such as ease of implementation, elimination of the unobservable wafflemode, potential noise gain reduction, and measurements which permit both linear and non-linear (branch-cut) phase reconstruction. This design will be fully evaluated, analytically and in simulation, and fine-tuned as necessary. This proposed sensor design will improve phase gradient measurement precision in high scintillation, resulting in increased Strehl ratio performance of a conventional least-squares reconstruction. It will also support the use of branch-cut phasereconstruction.