Low-loss slow-light in periodic plasmonic waveguides

We have proposed and investigated two kinds of waveguide systems (i.e., dielectric-dielectric-metal and dielectric-metal-dielectric waveguides) which are able to support low-loss slow-light guided mode at telecommunication regime of 1.55 μm. Simulation results demonstrate that the propagation length of the proposed waveguides is as long as tens or even hundreds of micrometers, which is more than ten times higher than that of the traditional metal-dielectric-metal waveguides. Moreover, the proposed waveguides have better slow light performance and a figure of merit that can reach a value as high as 18 000. In addition, the slow-down factor can be flexibly tuned by adjusting the geometrical parameters. The proposed waveguide have advantages of low loss and compact configuration, which can find potential applications, such as optical buffers, in highly integrated optical communication systems.