Band structure for dissimilar electromagnetic waves in a periodic structure

Abstract
Gaps occur in the dispersion relation for a wave propagating in a periodic medium. We observe that for dissimilar electromagnetic waves supported in corrugated thin-metaldielectric geometries such gaps are also present. Both an ω (frequency) gap and an apparent k (wave-vector) gap occur in a single dispersion curve with the ω gap resulting from the avoided crossing of the dispersion curves of two dissimilar electromagnetic waves.