Longitudinal electromagnetic waves with extremely short wavelength

Electromagnetic waves in vacuum and most materials have transverse polarization. Longitudinal electromagnetic with electric field parallel to wave vector are very rare appear under special conditions a limited class of media, for example plasma. In this work, we study the dispersion properties an easy-to-manufacture metamaterial consisting two three-dimensional cubic lattices connected metallic wires inserted one into another, also known as interlaced wire medium. It is shown that supports longitudinal at extremely wide frequency band from low frequencies up Bragg resonances structure. The feature unprecedentedly short wavelengths comparable period material. revealed effects highlight spatially dispersive response medium provide route toward generating fields strong spatial variation.