Fresnel zone interferometric imaging


Fourier analysis in projective coordinates shows similar inversion in the Fresnel zone. Since the longitudinal resolution of 3D coherence imaging falls inversely in the square of range in both the Fresnel and Fraunhofer zones, extension to the Fresnel zone dramatically improves longitudinal resolution by removing far-field range constraints. The utility of this method is demonstrated using rotational shear interferometers (RSI), which measure complete planes of coherence measures in a single frame. These experiments demonstrate that the incoherent field in an aperture may contain substantially more object information than conventional imaging systems detect.