Patent ID: 7094517

Claim:
A recording layer for write-once-read-many (WORM) optical disks with fluorescent reading, comprising: a fluorescent dye capable of absorbing recording laser radiation, present in an amount of about 0.1 weight percent to 10 weight percent of the recording layer; a non-fluorescent dye capable of absorbing recording laser radiation and transforming the absorbed radiation to heat; a compound that generates free radicals to decolorize the fluorescent dye, non-fluorescent dye, or both as a result of decomposition under heating induced by laser-radiation absorption by the fluorescent dye; and a film-forming polymer, wherein the compound that generates free radicals is selected from the group consisting of azo-bisisobutyronitrile, p-bromobenzene diazohydroxide, triphenylmethylazobenzene, diazobenzoyl, nitrosoacetanilide, peroxides, and a mixture thereof, and the recording layer is 100 nm to 1000 nm in thickness.