Phase Control by Polarization in Coherent Spatial Filtering

A new and simple technique for 0° or 180° phase generation for spatial filters has been developed. The method employs photographic printing and polarized light. Among the possible applications are those of symmetrical shape detection and image enhancement.The phase-control concept was developed using an optical spatial-filtering apparatus for matched filtering. Although the examples given are from the target-recognition field, the application of the method is in no way limited to this field.