Guiding Properties of 1.31-and 1.55-μm-Wavelength Surface Plasmon Polaritons on Striped Waveguides on Silicon and Their Wavelength-Selective Detection

We have analyzed the propagation behavior of 1.31-and 1.55-μm-wavelength-band surface plasmon polaritons (SPPs) for three simple Si-based plasmonic waveguides: the Au stripe waveguide, the SiO2 stripe waveguide, and the Au/SiO2 stripe waveguide on a Si substrate. The SPP propagation length in the waveguide varied depending on the waveguide structure and propagation lengths for waveguides with different structural parameters are summarized. The energy that was required for SPP detection after propagation along the waveguides for the 1.31- and 1.55-μm-wavelength bands was calculated for intensity-modulation direct-detection and heterodyne frequency-shift keying systems. The results demonstrate that SPPs can propagate with lower energy consumption than conventional electric wiring below a specific interconnect length. A wavelength-selective structure for SPPs that comprised nano-slits in an Au film on an Si substrate was fabricated. The device can selectively detect 1.31-μm-wavelength SPPs as electrical signals and transmit 1.55-μm-wavelength SPPs. Experimental photoresponses and transmittances were measured and compared with calculated results. Magnitude correlation of the measured and calculated photoresponses and transmittances showed good agreement. Evaluation of the SPP propagation behavior and the wavelength-selective structure are important considerations for the development of optoelectronic integrated circuits that use SPPs and electrons as signal carriers.