Abstract
We have developed a method to add an individual information to each DVD-ROM disk. Aluminum reflective layer is selectively removed to form stripes of 10 μ m wide overlapping pre-pits by converging pulse laser beam from a CW-Q switch type YAG laser. An information of at most 188-byte can be recorded by forming a series of these uniform stripes with intervals modified according to the information on the circumference of the disk. This recording method has been optionally adapted in DVD specification as BCA (Burst Cutting Area). In the readout signal read by an optical pickup, signal level drops to almost zero according to the stripes. The BCA data can be decoded by software in a CPU after removing the high frequency component by a simple low pass filter.
