Information-recording process in which a pulsed laser produces recording marks in the form of crisply-defined areas of surface relief on the surface of a recording medium such as APIEZON W wax, iodine doped epoxy resin, and other materials. The medium is selectively producable in different density states...http://www.google.com.au/patents/US4264986?utm_source=gb-gplus-sharePatent US4264986 - Information-recording process & apparatus
