ELECTROOPTICAL EFFECTS OF SINGLE-CRYSTALLINE FILMS OF FERROELECTRIC COPOLYMERS OF VINYLIDENE FLUORIDE AND TRIFLUOROETHYLENE

''Single crystalline'' (SC) films of vinylidene fluoride (VDF) and tri fluoroethylene (TrFE) copolymers (P(VDF/TrFE)) which are highly double -oriented films, do not form an intricate highly ordered structure, fo r example, a lamellar structure, but a simple one. After a SC film is poled under a de electric field, one-to-one correspondence can be obse rved between the macro-(drawn and poling axes) and optical axes in a S C film of P(VDF/TrFE). Therefore; linear electrooptical effects of SC films of P(VDF/TrFE) can be measured at room temperature and constant stress. We then found a large electrooptical coefficient in SC films o f P(VDF/TrFE).