5 inch (12cm) rewritable optical disc capable of recording in single, sided (23GB) or two layers (50GB). By achieving a track pitch of 0.32ìm, with state-of-the-art manufacturing technology and by utilizing blue-laser technology, the disc media can attain high density recording more than 5 times (23GB) or 10 times (50GB) than that of a DVD (4.7GB) using red-laser technology.