laser disk

CIDE DICTIONARY

laser disk, n. 

 A digital data storage medium consisting of a thin disk onto which the data is impressed by a laser, in the form of a linear sequence of dots; same as optical disk. The data is subsequently read back by the use of a laser beam. See also compact disk.
"The original disk may be created by use of a laser, but copies of the original disk may be created by a replicating process which does not itself require a laser."  [PJC]