Optical disc, information recording method, information reproducing method, and disc drive

摘要

A write-once optical disc which uses a short-wavelength laser (wavelength = 600 nm or less) allows BCA information recording even using a long-wavelength laser (wavelength falling within a range from 600 nm to 800 nm). To this end, a groove is cut in advance on a BCA part on a molded substrate of the optical disc to store a dye. In this way, the sensitivity of the dye in the BCA increases, to allow a laser having a wavelength (a wavelength falling within the range from 600 nm to 800 nm) other than the wavelength (e.g., 405 nm) corresponding to information recording of the dye to record a barcode pattern on the BCA.