Comparison of a Shack-Hartmann and distorted grating wavefront sensor using WaveTrain™ simulation software

The concept of a curvature-based wavefront sensor using a distorted grating as the imaging element to capture images of two spatially separated planes onto a single detector has been reported previously. This presentation reports on simulations comparing a Shack-Hartmann (S-H) sensor with a distorted grating wavefront sensor (DGWFS) for a generic adaptive optics (AO) system using a Clear-1 atmospheric model. Using WaveTrain(TM) simulation software a model of the DGWFS has been developed and integrated into the software. A simulation of a complete AO system including a tip/tilt system, high order correction system, atmospheric model, and a back-propagating laser system has been constructed. The model has then been exercised using various seeing conditions, noise levels, WFS sensitivities, camera systems, and other parameters. A comparison between the performance of the AO system using the S-H sensor and the DGWFS is presented, both in terms of wavefront measurement accuracy, image quality, and as a beam delivery system.