Two and three primary colors derived from an He-Ne gas laser and an argon gas laser were employed in recording and reconstructing holograms. For the tricolor case it is possible to reconstruct a three-dimensional multicolor image which possesses almost all the natural hues of the original object. Each wavelength generates an independent fringe system that is recorded on a photographic plate with a thick emulsion that constitutes a three-dimensional recording medium. In reconstruction, each fringe system diffracts light in a manner satisfying the Bragg relation for a particular reconstructing wavelength. If the reconstruction wavelengths are the same as the original wavelengths used to record the fringe systems, the result is a multicolor reconstruction possessing few or no ghost images. In our experiments, the angle between the object beam and the reference beam was greater than 100°, and the photographic plates were oriented so that the fringe surfaces were approximately perpendicular to the emulsion surfac This minimized the deleterious effects of single-color, ghost image formation and shrinkage during development. Finally, a method of synthesizing multicolor scenes using a multiple-exposure recording with one wavelength and reconstructing with several wavelengths is described.
A. A. Friesem and R. J. Fedorowicz, "Multicolor Wavefront Reconstruction," Appl. Opt. 6, 529-536 (1967)