Multilevel read-only optical recording methods

The advantages of read-only storage is the predominance of optical recordingrelative to magnetic and other rewritable methods. Multilevel (ML) read-onlytechnology has been a trend to improve the data capacity and transfer rate. Based onthe principle and coding method of ML, this paper demonstrates some ML read-onlyrecording methods, of which a new ML read-only recording is developed. Thisrecording method integrates amplitude modulation achieved by the reaction mechanismof physics and chemistry of photoresist with the run-length-limited technology. Thediscs can be achieved using standard photoresist mastering and replicationtechniques with great compatibility to conventional binary read-only discs.