Patent ID: 6027855
Filing Date: 2000-02-22
Classification: B82Y,G03C,G11B,G11C,Y10S

Abstract:
A method for the recording of information within an optical, write once read many times memory system comprising an active medium material capable of storing information in three dimensions, said active medium material including at least one Rhodamine B compound, said method comprising the steps of illuminating said active medium material so as to induce a photochemical reaction of said Rhodamine B compound from a Rhodamine B lactam having structure D to a fluorescent Rhodamine B derivative having structure E, ##STR10## where Y is o-, and m-nitrophenyl; m-halogenphenyl; p-fluorophenyl, p-iodophenyl and o-, m- and p-alkylphenyl (alkyl-C.sub.1 -C.sub.18) and wherein said information is recorded in said active media by formation of said fluorescent Rhodamine B derivative.