It was of course Dennis Gabor who, as long ago as 1948, published the fundamental work the principle of holography. But it was not until Theodore Maiman's invention of the laser in 1960 that the practical realisation of holography became possible. This was achieved by Leith and Upatnicks between 1962 and 1964, with the crucial impetus being provided by Vander Lugt (the author wishes to acknowledge the assistence of A. Vander Lugt, who, while performing work of a relatet nature, showed him the value of the gas laser as a light source). 1964 was the year in which Denisyuk presented his first portrait holograms in Leningrad. The many publications of Stroke of the University of New York were a source of numerous impulses. It is to this period, too, that my own first experiences date back. Together with my teacher. Ulrich Grigull, whom I hold in the highest regard, I constructed the first laser interferometer for the study of heat transfer and developed the initial ideas for holo-graphic interferometry. Then, in 1965, came the work of Hildebrandt and Haines and of Powell and Stetson in the United States in this field, and it was around this time, too, that Nassenstein and his colleagues Riek and Bestenreiner began their work in this new area in Germany.