Direct observation of Anderson localization in plasmonic terahertz devices.

ABSTRACT: We present the first experimental observation of Anderson localization in the terahertz frequency range using plasmonic structures. To accomplish this goal, we designed THz waveguides consisting of a one-dimensional array of rectangular apertures that were fabricated in a freestanding metal foil. Disorder is introduced into the waveguide by offsetting the position of each aperture by a random distance within a prescribed range. For example, for a waveguide with apertures spaced by 250??m in a periodic waveguide, 10% disorder would correspond to the apertures being shifted by a random value between ±25??m along the waveguide axis. We find that for disorder levels below 25%, there is only an increase in the propagation loss along the device. However, for two specific waveguides with 25% disorder, we observe a spatially localized mode that lies just within the stop band of the device and exhibits a double-sided exponential spatial decay away from the maximum.

SUBMITTER: Pandey S 

PROVIDER: S-EPMC6062171 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature