We show that properties attributed to planar metamaterials that support resonances due to an appropriately shaped unit cell can also be identified in a medium that exhibits a resonance evoked by its period only. By choosing a subwavelength period, the effective material parameters of such a medium can be retrieved from the complex reflected and transmitted amplitude. The parameters exhibit Lorentzian line shapes in the spectral vicinity of the resonances associated with the period. If this material is stacked to form a three-dimensional medium, a stop gap is observed in transmission in the frequency range where the real part of one effective material parameter becomes negative. The resonance at the origin of the response is related to the excitation of a higher-order Bloch mode. Because their negligible excitation is a prerequisite for deriving effective material parameters, the analyzed structure mimics only the response of a metamaterial but cannot be regarded as a metamaterial.
© 2007 Optical Society of America
Original Manuscript: January 3, 2007
Revised Manuscript: May 11, 2007
Manuscript Accepted: May 15, 2007
Published: September 21, 2007
Photonic Metamaterials (2007) JOSA A
Carsten Rockstuhl, Ulf Peschel, and Falk Lederer, "A periodic structure mimics a metamaterial," J. Opt. Soc. Am. A 24, A60-A65 (2007)