Optical memories, method for reading and writing such optical memories, and device for reading and writing such memories

摘要: The invention concerns a optical data memory, said memory comprising at least one layer of Supporting material, said Supporting material including molecules having, in a local Zone, a collective state of molecules from at least one first collective state of molecules, and a second collective state of molecules. The invention is characterized in that only mol ecules having the first collective state of molecules in said local Zone are capable of generating a second-harmonic sig nal when they are excited in said local Zone by a reading electromagnetic radiation.