CD writer generates holograms

Researchers from Cambridge University in England have found a way to turn an ordinary CD writer into a device that burns two-dimensional holograms onto CDs.

The researchers' scheme bypasses the error correction system of a CD writer and interjects its own data as the device lays down CD tracks. The system monitors the CD's rotation in order to keep track of where on the CD it is writing.

Holograms are useful for routing light in a complicated fashion to, for example, switch light signals between optical fibers. Computer-generated holograms used for this purpose are generally created using a relatively expensive pressing process. The researchers' method could also be used to watermark a disk during recording. Because the images are holograms, they would be difficult to reproduce.

The modifications to an ordinary CD writer can be done at almost no cost, the hologram quality is similar to pressed holograms, and the method is very fast, according to the researchers. They are looking into modifying a DVD writer, which has narrower tracks and thus should be able to produce finer, and even three-dimensional, holograms.

The researchers' method could be implemented using ordinary CD writers within a year, according to the researchers. The work appeared in the September, 2003 issue of Optical Engineering.