Phase-noise type broad spectral bandwidth optical low-pass anti-aliasing filter

A device is described for a very low cost anti-aliasing filter to be used to suppress aliasing artifacts present in discretely sampled solid-state electronic imaging devices. This device includes a transparent substrate upon which a multiplicity of transparent phase spots are placed. The diameter and thickness of the transparent phase spots are designed in such a way to cause just the right amount of blurring to suppress the aliasing artifacts, yet render a reasonable sharp image for spatial frequencies below the sampling frequency of the imager. This suppression is further accomplished over a broad spectral range. The phase noise filter thus formed can be placed either in object space or in image space.