Subwavelength lateral confinement of microwave surface waves

Experimental verification of the “domino plasmon,” recently proposed by Cano et al. [Opt. Express 18(2), 754, (2010)] is presented. Using microwaves, it is demonstrated that this mode propagates along a periodic chain of metallic cuboids (“dominos”) and the dispersion of the mode is determined with results being compared to the predictions of analytical and numerical models. This mode is found to be surprisingly insensitive to the lateral width of the chain, even on a subwavelength scale. Having such tight confinement, “domino plasmons” show considerable promise for one-dimensional subwavelength guiding and focusing of electromagnetic fields.