Decker A J, Pao Y H, Claspy P C
Appl Opt. 1978 Mar 15;17(6):917-21. doi: 10.1364/AO.17.000917.
The use of a phase-modulated reference wave for the electronic heterodyne recording and processing of a hologram is described. Heterodyne recording is used to eliminate the self-interference terms of a hologram and to create a Leith-Upatnieks hologram with coaxial object and reference waves. Phase modulation is also shown to be the foundation of a multiple-view hologram system. When combined with hologram scale transformations, heterodyne recording is the key to general optical processing. Spatial filtering is treated as an example.