Existing comment:
Toy train hologram with model
1963
developed by Emmett Leith and Juris Upatnieks at the University of Michigan
Scientists at an April 1964 conference gazed in awe at this experimental hologram, Toy Train. Physicists Emmett Leith and Juris Upatnieks used a laser to make the three-dimensional image from the model train displayed above. While not the first, Toy Train proved that high-resolution holograms were possible and inspired other researchers to extend the technology.
Leith and Upatnieks split a red laser beam and aimed half at the glass photographic plate, the other half reflected off the model and onto the plate. When recombined the beams created a pattern of light waves on the plate. The image only appears when a precisely aimed laser lights, the plate. Today, holograms can be seen in ordinary light appear on credit cards and security tags. |