ABSTRACT
It has been 11 years since I attended that —rst seminar on puri—ed deoxyribonucleic acid (DNA) given by Professor Naoya Ogata from the Chitose Institute of Science and Technology. At that seminar, Ogata discussed a new process that he developed for deriving DNA from —sh milt and roe sacs, waste products of the salmon industry in Hokkaido, Japan. He puri—ed it by removing 98% of the proteins and stabilizing it with a cationic surfactant to render it water insoluble, but dissolvable in alcohols. You have read about the process in depth in Chapter 7. He displayed a sample of a puri—ed DNA-surfactant free-standing —lm that he had cast to illustrate the optical transparency of DNA. Working with nonlinear optical (NLO) polymer electro-optic (EO) modulators at the time, I was looking for optical cladding materials with an electrical resistivity one to three orders of magnitude lower than that of the NLO core material, an optical propagation loss no more than two times that of the core material, and resistance to the organic solvents used to dissolve the core material. In order to optimize the performance of NLO polymer EO modulators, top and bottom cladding materials with all of the foregoing desired properties listed were needed. However, all the polymers that were identi—ed with the desired electrical resistivity had more than 10 times the desired optical loss, and polymers that had the desired optical loss had 10-1000 times the desired electrical resistivity. In addition, the solvents used to dissolve the NLO core material would also dissolve the cladding materials, rendering stacking these materials to fabricate waveguide structures problematic to say the least.
