Triangular metal wedges for subwavelength plasmon-polariton guiding at telecom wavelengths

We report on subwavelength plasmon-polariton guiding by triangular metal wedges at telecom wavelengths. A high-quality fabrication procedure for making gold wedge waveguides, which is also mass-production compatible offering large-scale parallel fabrication of plasmonic components, is developed. Using scanning near-field optical imaging at the wavelengths in the range of 1.43–1.52 µm, we demonstrate low-loss (propagation length ~120 µm) and well-confined (mode width ≅1.3 µm) wedge plasmon-polariton guiding along triangular 6-µm-high and 70.5°-angle gold wedges. Experimental observations are consistent with numerical simulations performed with the multiple multipole and finite difference time domain methods.