Polymer-based long-range surface plasmon polariton waveguides for 10-Gbps optical signal transmission applications

We present characteristics of very thin An strip waveguides based on long-range surface plasmon polaritons (LR-SPPs) along thin An strips embedded in polymers. We also report a 10 Gbps optical signal transmission via LR-SPPs with the pig-tailed An strip waveguide at a telecommunication wavelength of 1.55 mu m. We limited the thickness, width, and length up to similar to 20 nm, similar to 10 mu m, and similar to 5 cm, respectively, for practical applications. At 1.55 mu m, loss properties of the An strip waveguides were theoretically and experimentally evaluated with thickness, width and cladding material. The lowest propagation loss of similar to 1.4 dB/cm was experimentally obtained with the 14-nm-thick and 2-mu m-wide An strip. With a single-mode fiber, the lowest coupling loss of less than 0.1 dB/facet was achieved with the 14-nm-thick and 7.5-mu m-wide An strip. The lowest insertion loss was obtained 7.7 dB with the 14-nm-thick, 5-mu m-wide, and 1.5-cm-long An strip. The propagation loss was improved approximately 30% for the 17-nm-thick An strip with lowering the refractive index of the cladding polymer by 0.01. In the 10 Gbps optical signal transmission experiment, the LR-SPP waveguide exhibits an excellent eye opening and a 2.2 dB power penalty at 10(-12) bit error rate. These all results indicate that the LR-SPP waveguide is a potential transmission line for optical interconnects to overcome inherent problems in electric interconnects.