Pit Depth and Width Modulation Multilevel Run-Length LimitedRead-Only Optical Storage

Abstract

When the techniques of integrating the variation of the pit depth andwidth simultaneously are adopted to conventional DVD, the high-densitymultilevel run-length limited read-only optical storage method isachieved. The dynamic range of readout signal is greatly enlarged incomparison with keeping one parameter varied, and the recording levelsnumber can be obviously increased. The discs can be manufactured usingstandard photoresist mastering and replication techniques with greatcompatibility to conventional binary read-only discs. Experimentalresults show that eight-level read-only optical disc can be realizedand the capacity can be increased to 20 GB.