Effects of lithographic roughness and sidewall slope on the optical performance of polymer rectangular waveguides: Modeling

Fabrication of polymer, multimode, channel waveguides have gained much attention recently because of usefulness in replacing fiber in backplane interconnects. Waveguides are more desirable because they are able to achieve greater bandwidth, they are immune to electromagnetic interference and they consume less power compared to traditional electrical communication links. They are however subject to insertion losses due to fabrication defects such as the waveguide sidewall roughness and sidewall slope. This requires fabrication tolerances that are on the micron level. Determining the acceptable minimum tolerances required in the fabrication process in terms of the overall channel link budget is critical for determining how precise of fabrication methods must be utilized.