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 silicaphotonic 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 � 10 5 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. � Springer-Verlag 2012.