Abstract: A wavefront sensing and compensating system for detecting and correcting for distortion in light wavefronts is described in which the wavefront is divided into a plurality of subapertures and light intensified and imaged as spots of light from each subaperture onto a detector array. The individual detector elements of the array form a plurality of electrical signals proportional to the local divergence of the vector gradient field (.gradient..sup.2 .phi.). This .gradient..sup.2 .phi. signal after interfacing or reconstruction is applied to corrective mirrors which may be of the deformable or membrane type.

Abstract: A wavefront sensor for detecting distortion in light wavefronts is described in which the wavefront is divided into a plurality of subapertures and light amplified or intensified and imaged as spots of light from each subaperture onto a filter mask. The filter mask encodes a predetermined function of the spot intensity distributor onto the light intensity of the spot transmitted through the filter. For spot centroid calculation, the function is linearly variable. Mask embodiments include linearly varying alternate opaque and transparent chevrons, electronically variable chevrons, and quadratically varying chevrons.

Abstract: Apparatus for maintaining image definition and intensity in optical image processing operations. The apparatus comprises an improved photosensitive device responsive to an applied radiation image pattern for establishing internal electric fields each of which are representative of the intensity of different portions of the applied pattern. Associated with the photosensitive device are a plurality of transparent, conductive targets or conductors aligned to receive the different portions of the applied radiation pattern and to establish discrete internal fields in the device which are uniform over the area of each target notwithstanding any non-uniformities that might exist in the intensity distribution of any of the portions of the applied pattern.