[12a-N107-1~5] 3.1 Basic optics and frontier of optics

[12a-N107-4] Simulation of Dark Plasmon Modes Excitation by Terahertz Longitudinal Electric Field Pulses

〇(D)Mizuho Matoba¹, Kuniaki Konishi¹, Norikatsu Mio¹, Junji Yumoto¹, Makoto Kuwata-Gonokami¹ (1.Grad. Sch. Sci., UTokyo)

Keywords:vector beam, longitudinal electric field, dark mode

Dark plasmons in metal structures have attracted much attention because of their low radiation loss. They do not couple with the propagating light, so various excitation methods have been studied, such as introduction of asymmetry into metal structures, excitation by propagating light with non-uniform polarization and phase distribution, and excitation by near-field emitters. In this study, we propose using a longitudinal electric field of light as a novel method to excite dark plasmon modes in a metal rod. The longitudinal electric field is a localized electric field generated near the radial beam focal point and oscillating in the direction of light propagation. We performed numerical calculations using three-dimensional finite element method in the terahertz region to investigate characteristics of the excited resonant modes. The results imply that using longitudinal electric fields is effective for non-contact excitation, detection and control of dark plasmon modes.