TECHNOLOGICALLY USEFUL NLO FILMS OF POLYPHENYLENE VINYLENE AND ITS COPOLYMERS

CERTAIN CONJUGATED ORGANIC POLYMERS POSSESS INTERESTING NONLINEAR OPTICAL PROPERTIES. TO DATE THERE EXIST SEVERAL OF THESE POLYMERS BUT ALTHOUGH THEY MAY HAVE LARGE THIRD ORDER NONLINEAR SUSCEPTIBILITIES, X(3), THEY MAY LACK THE NECESSARY OPTICAL QUALITY (LINEAR OPTICAL PROPERTIES), MECHANICAL PROPERTIES, OR LASER DAMAGE THRESHOLD TO BE OF PRACTICAL INTEREST. THE PROPOSED EFFORT WILL DETERMINE THE OPTIMUM PROCESSING CONDITIONS FOR A CLASS OF POLYMERS WITH A REPORTEDLY HIGH VALUE OF X(3), MEASURE THE NONLINEAR OPTICAL PROPERTIES,AND DETERMINE THE LINEAR OPTICAL PROPERTIES. THE CLASS OF POLYMERS IS THE POLYARYLENE VINYLENES. DEGENERATE FOUR WAVE MIXING (DFWM) EXPERIMENTS WILL BE PERFORMED TO ASSESS X(3). THE LINEAR OPTICAL PROPERTIES WHICH WILL BE EVALUATED ARE OPTICAL TRANSPARENCY AND OPTICAL FLATNESS. POLYARYLENE VINYLENES POTENTIALLY OFFER THE UNIQUE ADVANTAGES OF LIQUID CRYSTALLINE ORDER WITH THE POSSIBILITY OF MATCHING ELECTRIC FIELD DIRECTION TO ORIENTATION OF POLYMER, USEFUL OPTICAL WINDOW FOR SIGNAL PROCESSING, HIGH LASER DAMAGE THRESHOLD DUE TO AROMATIC STRUCTURE, AND THE POTENTIAL TO MOLECULAR ENGINEER PROPERTIES AND PROCESS INTO DESIRED ARCHITECTURES, PARTICULARLY FILM. THESE ARE SIGNIFICANT BENEFITS OVER EXISTING INORGANIC MATERIALS SUCH AS LITHIUM NIOBATE AND POTASSIUM HYDROGEN PHOSPHATE, WHICH ARE DIFFICULT TO PROCESS, DEGRADE RAPIDLY AND ARE FRAGILE.