Spatial frequency notching by source modification.

A partially coherent image-enhancement system is introduced for notching unwanted spatial frequency components. The technique offers two advantages over a more conventional coherent spatial-filtering approach. First, the method utilizes a fixed pupil mask and a dynamic source and eliminates the need for a high-optical-quality spatial light modulator. Second, the redundancy that is introduced by the source provides greatly improved immunity to the effects of optical setup noise (dust, scratches, and other imperfections on optical surfaces). Numerical simulations and a laboratory experiment support the analysis.