Abstract: A monolithic optical device formed from a GRIN rod having a centered aperture at an exit end thereof is bonded to a laser exit face to couple laser radiation through a spatial aperture without the alignment sensitivity characteristic of the prior art by the sequence of fabrication and alignment steps, whereby the output beam from the spatial filter is essentially subject only to vignetting as a result of misalignment of the optic with respect to the laser beam, rather than to the distorted wavefront characteristic of such misalignment in the prior art.

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.