SURFACE ORIENTED POLYMERS FOR NONLINEAR OPTICS

A large number of criterion must be met for a material to be of practical value in the development of wave guide optical switches. We have taken the approach that optimal and permanent orientation is of prime importance. We have addressed the question of alignment by developing techniques for the polymerization of aminoacids to form vertically oriented helices on gold surfaces. Using this approach, we have been able to grow layers of alanine, methylalanine (ethylglycine), leucine, and phenylalanine on gold deposited on silicon that are 1-2000 A thick. Further, grazing angle, FTIR measurement are consistent with the presence of only helical peptides for alanine and 90-95% helical forms of the peptides derive from the other aminoacids. These helical columns are oriented to a major extent vertically relative to the surface. The key feature that of the technique is the use of a base attachment for the gold surface that maps out the correct surface area corresponding to that required for the