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

Abstract

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 microm, we demonstrate low-loss (propagation length approximately 120 microm) and well-confined (mode width congruent with 1.3 microm) wedge plasmon-polariton guiding along triangular 6-microm-high and 70.5 degree-angle gold wedges. Experimental observations are consistent with numerical simulations performed with the multiple multipole and finite difference time domain methods.