Thin film and interferometric optical disk media and mass production method for fabricating such and multi-layer CDS

An optical disk, comprising:

• a first transparent layer having a pattern of variations in thickness between a first thickness "d1" and a second thickness "d2" that differ from one another sufficiently as fractions of a light wavelength to cause a substantial interferometric difference in a first reflected beam of incident laser light between said first thickness "d1" and said second thickness "d2";
• and
• a first reflective layer deposited on the pattern side of the first transparent layer providing for returning said first reflected beam of incident light toward a laser light source for detection of a first information patterned in a plan distribution of said first and second thickness "d1" and "d2".

A data storage medium, comprising:

• interferometer means for storing digital information in a plastic film and reflective film combination by patterning a variation of said plastic film thickness between two thickness, each thickness corresponding to substantially different fractions of a single monochromatic light wavelength.