Patent ID: 6998214

Claim:
A method for writing optical data with three-dimensional resolution in an optical storage material comprising a compound of the formula wherein R, R′ and R″ are each independently H, halogen atom, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxy carbonyl, alkylamino, alkylthio, alkylsulfonyl and alkylsulfinyl each optionally substituted with an alkyl, halogen, alkoxy, aryl or a heteroaryl group comprising the steps of: a) producing a single intense beam of focusable coherent light; and b) focussing the beam on a photosensitive three-dimensional optical storage medium having the optical storage material to produce at least three photon excitation within said material at the focal point of said beam to thereby produce a detectable characteristic change in said material.