Real-time wavefront reconstruction for a 512 subaperture adaptive optical system

This paper describes a system capable of real-time wavefront reconstruction for a 512 subaperture shearing interferometer. The system was designed to interface with a 1536 channel (512 segment) deformable mirror for atmospheric compensation using an artificial beacon. The phase gradients were measured using a shearing interferometer operating at two distinct shear lengths with quantum limited performance at 200 photons per subaperture. A 128 node parallel processor performed a sparse matrix multiply to reconstruct the phasefront in real time. The matrix truncation technique used allowed 90% of the elements to be removed with only minor penalty in wavefront accuracy.