THz Near-Field Responses of Subwavelength Metallic Structures

Event Date: April 8, 2011
Speaker: Hannes Merbold
Speaker Affiliation: University of Bern
Time: 10:30 am
Location: EE 317
Contact Name: Professor Kevin Webb
Contact Email: webb@purdue.edu
Open To: ACCEPTABLE FOR ECE 694A

The last decade has seen significant progress in the development of a novel class of materials which may exhibit intriguing optical properties not found in nature. These metamaterials gain their properties through subwavelength metallic inhomogeneities such as arrays of split-ring resonators (SRRs). We employ different experimental THz techniques as well as numerical simulation tools to investigate the response of SRRs in the near-field regime. This allows us to map the field distribution behind the samples at the different order resonances or to visualize the near- to far-field evolution of THz radiation interacting with the structures. Coupling effects between neighboring SRRs in arrays or between sub-elements within the unit cell are found to result in linewidth sharpening, resonance hybridization, the excitation of dark resonances, or metamaterial induced transparency.

In addition, we investigate metallic micro- and nanostructures which can be used to increase the resolution in THz near-field microscopy or as field enhancing devices for nonlinear THz experiments.