Opto-ferroelectric memories using vinylidene fluoride and trifluoroethylene copolymers

It is shown how ferroelectric polymers can be applied to an erasable optical memory. The medium developed consists of a dye-doped vinylidene-fluoride-trifluoroethylene copolymer film with a thickness of 2 mu m, spin-coated onto an ITO-coated glass plate. Information is written in terms of sequences of positive and negative polarizations generated by irradiating a focused laser beam of approximately 5- mu m diameter, in the presence of sign-controlled electric fields. The data are read out pyroelectrically by scanning the laser beam. A C/N ratio of 48 dB has been obtained for the 0/1 data train, in a 20- mu m pitch.<
>