procedure for reproduction of an hologrammes, the function of optical principles of complex wellenaenderungsanordnung ausuebt with high fidelity

摘要

The method of reading out the type of hologram which results from the simultaneous recording on a recording medium surface of first and second components of coherent wave energy, wherein the first component consists of a beam traveling substantially in a given direction with respect to the surface and wherein the second component has been operated on by a particular complex wave modifying structure working on the principles of optics, such as an array of lenses lying in a plane parallel to the medium surface. Readout is accomplished with a readout beam of incident wave energy traveling substantially in the direction with respect to the medium surface which is opposite to the aforesaid given direction. Object information may be also recorded on the hologram by spatially modulating the first component with the object information, or object information may be obtained during readout by spatially modulating the readout beam with object information. In either case, high fidelity reconstruction is obtained, which depends both on the object information and the particular complex wave modifying structure utilized in making the hologram. In the case where the structure is a lens array, multi-imaging of the object information is obtained. Also, in the case where object information is obtained by spatially modulating a readout beam which has been diffused by a diffuser, speckle noise normally present in the reconstructed image may be eliminated by destroying the coherence of the wave energy for example by rotating the diffuser during readout.