Abstract-Detection of internal fields in double-metal terahertz resonators

Oleg Mitrofanov1,2,a), Zhanghua Han3,a), Fei Ding4, Sergey I. Bozhevolnyi4, Igal Brener2,5, and John L. Reno

http://aip.scitation.org/doi/10.1063/1.4975802

Terahertz (THz) double-metal plasmonic resonators enable enhanced light-matter coupling by exploiting strong field confinement. The double-metal design however restricts access to the internal fields. We propose and demonstrate a method for spatial mapping and spectroscopic analysis of the internal electromagnetic fields in double-metal plasmonic resonators. We use the concept of image charges and aperture-type scanning near-field THz time-domain microscopy to probe the fields confined within the closed resonator. The experimental method opens doors to studies of light-matter coupling in deeply sub-wavelength volumes at THz frequencies.