Experimental techniques in making multicolor white light reconstructed holograms.

Because of the characteristics of the available white light sources, lasers and photographic emulsions, as well as the environmental condition of a laboratory, many practical problems are often encountered in making high quality multicolor holograms reconstructed in white light. The nature of the difficulties is discussed. Techniques useful to the solutions of these problems are presented, such as increasing the coherence length of a laser with little sacrifice in power, improving the signal-to-noise ratio in the reconstruction, controlling the shrinkage of the emulsion to eliminate color shift, and increasing the speed of Kodak 649F emulsion.