Differential holographic method

摘要

A differential holographic method and arrangement for measuring and testing the changing conditions of objects or articles, in which there are taken intermediate holograms of an unflawed reference object, and from which there are employed the reconstructed object waves of the reference object in order to illuminate the test object for a holographic exposure. Two reference beams record two intermediate holograms of the reference object on one holographic plate, and successively illuminate the test object with the reconstructed object wave fields from the intermediate holograms with utilization of the associated conjugated reference beams.