Apparatus for evaluating holographically reconstructed wave fields with two frequencies

摘要

Apparatus for evaluating the reconstruction of holographically recorded wave fields wherein the same spatial arrangement of the reconstructing apparatus with respect to the recording medium and the reference waves is utilized as in the recording process. The frequencies of the reference waves utilized during reconstruction are different than those used during recording. A geometric-optic arrangement focuses the reconstructed wave field in an image plane which is scanned by optoelectronic detection means. The undulating light signal produced in the image plane has a carrier frequency equal to the beat frequency between the frequencies of the reference waves utilized during reconstruction, and has a phase directly proportional to the depth of the object point under observation in the image plane.