Bloch Long-Range Surface Plasmon Polaritons on Metal Stripe Waveguides on a Multilayer Substrate
We propose and demonstrate a thin Au stripe on a truncated 1D dielectric photonic crystal covered with Cytop as a waveguide for Bloch long-range surface plasmon polaritons. High-quality mode outputs were observed and a mode power attenuation of 12-17 dB/mm measured at λ0 = 1310 nm for propagation in the plane of the truncated photonic crystal and within its stopband. The truncated 1D photonic crystal advantageously enables the use of a large range of materials for the substrate, breaking free from the constraint of material symmetry to support long-range plasmons. An input grating coupler implemented as a periodic array of nanoscale Au ridges on a Au stripe was used to excite the mode via perpendicularly incident p-polarized light. The output was provided by adding a second grating coupler near the end of a waveguide to diffract light upward or by polishing the output facet and allowing the mode to radiate into a free-space beam. Advantageously, grating coupling eliminates the need for high-quality end facets, and optical alignment is simplified. Given its practicality, the structure proposed is of strong interest for biosensing.
|Keywords||biosensor, Bloch, long-range, multilayer, photonic crystal, plasmon, surface|
Fong, N.R. (Norman R.), Menotti, M. (Matteo), Lisicka-Skrzek, E. (Ewa), Northfield, H. (Howard), Olivieri, A. (Anthony), Tait, R, … Berini, P. (Pierre). (2017). Bloch Long-Range Surface Plasmon Polaritons on Metal Stripe Waveguides on a Multilayer Substrate. ACS Photonics, 4(3), 593–599. doi:10.1021/acsphotonics.6b00930