Left-handed dispersion of a stack of sub-wavelength hole metal array et terahertz frequencies

Charles Croënne (1) , F. Garet (2) , Eric Lheurette (1) , J.-L. Coutaz (2) , D. Lippens (1)

1 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
2 IMEP-LAHC - Institut de Microélectronique, Electromagnétisme et Photonique - Laboratoire d'Hyperfréquences et Caractérisation

We report on the electromagnetic response of a stack of subwavelength hole metal arrays. The samples were designed for exhibiting left handed dispersion branches under normal incidence, and their transmissivities were optimized via the fabrication of elliptical-shaped holes. They are constituted of benzocyclobutene layers with tens of micron thicknesses and submicron-thick gold films patterned by photolithography. Experimental evidence, achieved by time-domain terahertz spectroscopy and supported by full wave simulations, of a ground left handed dispersion branch is found around 0.45 THz. The insertion losses are −3 dB for a five-layer structure, this good level being explained by the matching of the impedance.

Domaines: Optique [physics.optics]; Electromagnétisme

Charles Croënne, F. Garet, Eric Lheurette, J.-L. Coutaz, D. Lippens. Left-handed dispersion of a stack of sub-wavelength hole metal array et terahertz frequencies. Applied Physics Letters, 2009, 94 (13), pp.133112. ⟨10.1063/1.3114411⟩. ⟨hal-00991807⟩