A simple card to backplane polymeric optical high speed interconnect coupler for computer motherboards

High-speed optical card-to-backplane interconnects for computer motherboards are presented. In the system, we used evanescent coupling with fixed known coupled power for the horizontal waveguide coupler and almost fixed coupled power in the vertical waveguide coupler. The waveguides are single-mode rib structure having the advantage of higher values of core area for coupling from the source. The modal dispersion effect arising in multimode waveguides is avoided here and hence improves the bit rate performance. We used two types of fabrication process to prepare the polymeric optical waveguide: (A) Conventional process by patterning with mask, (B) PDMS (polydimethylsiloxane) mold as pattern. The experimental repeated results both for the types (A) and (B) show that the output power variation limits within 14%. The simulated BeamPROP results for the light coupling are compared with the theoretical and experimental results.