On the high performance of channel photonic crystal waveguide comprising different plasmonic active metals

Abstract

We present a detailed design principle and the propagation characteristics of a channel photonic-crystal-surface-plasmon waveguide (PCSPW), comprised of silica- photonic crystal waveguide (PCW) and plasmonic waveguide based on different plasmonic active metals such as gold (Au), silver (Ag) and aluminium (Al). We found that the phase-matching/resonance wavelength can be substantially tuned over a broad spectral range by judiciously choosing different plasmonic metals. The Al-based channel PCSPW has been found to exhibit ultra large group-velocity dispersion (∼±2.2×105 ps/km-nm), an extremely narrow bandwidth (4.5 nm) and long propagation lengths (∼400 % longer) as compared to Au-based channel PCSPW. The oxidation problem of Al has been addressed by using a bimetallic combination of Al+Au. Also, such a waveguide can be used as a sensor with a sensitivity as high as ∼5000 nm/RIU, thereby opening a new window for lab on chip.