Compression-molded three-dimensional tapered polymeric waveguides for low-loss optoelectronic packaging

We report for the first time, three-dimensionally tapered polymeric waveguides fabricated by the compression-molding technique. The waveguides presented herein provide a feasible solution to bridge discrete optoelectronic devices having apertures of a few micrometers to hundreds of microns. 1-cm-long tapered channel waveguides with the end cross sections of 5 μm×5 μm and 100 μm×100 μm were fabricated. These waveguides have a propagation loss of 0.5 dB/cm when the 632.8-nm He-Ne laser light is coupled from the small end and of 1.1 dB/cm when coupled from the large end. By confining the energy to the fundamental mode, when coupling from large end to the small end, a low-loss packaging can be achieved bidirectionally.