Optical data storage medium having interference and flattening layers each having specific thickness for improved information reading and tracking reliability

摘要

An optical data storage medium having a substrate, and an optical storage layer with a recording track or tracks for storing information to be read by a light beam. An interference layer is formed on the substrate, such that a tracking reflector defining the recording track or tracks is formed on the interference layer. A flattening layer is formed on the interference layer such that the flattening layer covers the tracking reflector and provides a flat surface on which the storage layer is formed. Each of the interference and flattening layers has a thickness substantially equal to 80 /8 or (&lgr;/8+m·&lgr;/2), where &lgr; represents a wavelength of the light beam as measured while the light beam is travelling through the interference and flattening layers, and m represents a natural number.