FABRICATION OF LOW-LOSS POLYIMIDE OPTICAL WAVE-GUIDES USING THIN-FILMMULTICHIP-MODULE PROCESS TECHNOLOGY

A simple, wet chemical patterning process for the fabrication of low l oss waveguides using photosensitive polyimides is described. Optically transparent, fluorinated polyimides are modified by co-polymerizing a low concentration of photocrosslinking groups into the backbone, The polyimides can then be patterned into arrays of channels, ribs, or Y b ranches, by UV exposure through a photomask followed by wet chemical d evelopment. Sidewall smoothness and sidewall profiles can be controlle d by varying exposure and development conditions, The resulting polyim ide waveguides are low loss and can be coupled into an optical fiber b y end-fire coupling, Results on channel guide coupling, propagation, a nd loss will be described.