Research on holography has now grown to such dimensions that we have not been able to mention each of the numerous authors who have made significant contributions to it. Investigators from Bell Telephone Laboratories, the RCA, Xerox, and Westinghouse laboratories, Conductron Corporation, GC-Optronics, IBM, TRW Systems, the University of Michigan, and Stanford University have made particularly significant early contributions in the United States. Especially notable were the efforts of R. J. Collier, L. Lin, K. S. Pennington, D. Ansley, L. Siebert, R. M. Grant, A. Lohmann, R. F. Wuerker, K. Stetson, R. Powell, J. Goodman, and their co-workers, in addition to those already mentioned, among many others. Early work in many parts of the world also includes that in France by S. Lowenthal, G. Nomarski, and J. Viepsilonnot; in Germany by H. Nassenstein; in Great Britain by J. M. Burch; in Japan by J. Tsujiuchi and T. Tsuruta; and in the Soviet Union by Yu. Y. N. Denisyuk, I. Nalimov, and L. M. Soroko. For a fuller account of these developments, see (42) and other references.