In figure 10 we have a typical Rainbow hologram recording setup [5]. A parallel reference beam REF illuminates the hologram plane H from below. Light from the same laser illuminates object O. Object O sends an object beam through a narrow horizontal slit in aperture plate AP, and this object beam is focused at the location of real image I. The object beam then continues on to the hologram plane H, where it illuminates a long narrow horizontal region. Optical interference produces a fringe pattern in this region. This fringe pattern is identical to that of a zoneplate lens, but it's a zoneplate lens which is masked down into the shape determined by aperture plate AP. The "horizontal band" shape of the interference pattern recorded on hologram H is critical to the operation of Rainbow holograms.
Essentially Figure 10 depicts the recording of a single-point rainbow hologram. As Siemens-Wapniarski and Givens [6] point out, such a process can be repeated sequentially, object-point by object-point, in order to "stamp" numerous zoneplate patterns onto hologram H. The result is nearly identical to conventional holography; only an undesirable phenomenon involving object-beam self-interference will be lacking. Alternatively the entire object O can be illuminated simultaneously to produce the usual rainbow hologram.