Abstract: Optical waveguide structures containing siloxane resin composistions as core materials and a method for preparing the waveguides are disclosed. The siloxane resin compositions can be cured by thermal energy or actinic radiation. In addition, conventional patterning techniques can be used, which makes the present method ideal for practicing on a commercial scale. The optical waveguides of the invention exhibit very low optical losses and are compatible with silicon processing requirements, which makes them useful in integrated circuitry. In addition, the high refractive index contrasts between the siloxane resin core and various claddings, including other siloxane resins, makes the waveguides particularly desirable.

Abstract: Diaryliodonium salts are disclosed, as well as a method for preparing them, in which one of the aryl groups bonded to the positively-charged iodine ion contains a methyl substituent, and the other one contains a hydroxyl-substituted alkoxy group. The salts are synthesized from (o, m, or p)-iodotoluene, as opposed to iodobenzene, and therefore do not pose a carcinogenic risk. In addition, the present salts are unexpectedly more soluble in most organic solvents, as well as in nonpolar monomers, than the corresponding benzene catalysts. The salts are useful as cationic photoinitiators, cationic thermal initiators (often combined with a cocatalyst, e.g. copper), and as starting materials in the synthesis of urethane-containing iodonium salts.