Formation of three-dimensional images when using selectograms and diffraction gratings

The results on the experiments on recording reference-free selectograms that reconstruct 3D images of objects are given. The selectograms were recorded by splitting the radiation of the object into two identical components with the help of diffraction gratings placed in front of a light-sensitive layer. The recording was performed on thin-layered inclined light-sensitive plates by using the method of pseudodeep holograms. The possibilities of recording reference- free selectograms of such a kind by a coherent radiation as well as by the radiation with a restricted spatial coherence were studied. In the case for which the selectogram was recorded by a coherent radiation, the radiation scattered by the object was split into two components by a diffraction grating placed in front of an inclined light-sensitive plate. The selectograms recorded in such a way reconstructed the volume images of objects whose resolution was sufficient for visual perception. For recording in an incoherent radiation an interferometer was suggested that was composed of two diffraction gratings which shifts the plane of the zero path difference of interfering beams into the center of the inclined photographic plate. The restriction of the coherence of the beam illuminating the object was performed by moving a diffusor that was used for illuminating the object-transparency. The selectogram recorded in such a way reconstructed the image being in a form of a luminous horizontal stripe corresponding to one of the horizontal cross-sections of the object being recorded. The experiment on the multiple recording of selectograms on one photographic plate at the successive displacement of the interferometer along the optical axis of the system has been carried out. In this case, the reconstructed image represented a system of horizontal luminous stripes each of them representing one of the lines of the image of the recorded object.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.