Abstract

Metallic wire grids (WG) are popular terahertz (THz) polarizing elements. For freestanding structures, the near perfect properties of metals provide high transmission efficiency and extinction ratio over a wide frequency range. For substrate-supported structures however, these nearly ideal properties are lost as the transmission efficiency is dictated by the refractive index of the substrate. Recently, double layer WG (DWG) structures have been proposed for their exceptional polarizing properties [1]. With the help of a semi-analytical model, we show here that such structures can act as excellent anti-reflection coatings for transverse magnetic (TM) waves. Experimental verifications on selected examples are provided.

© 2013 IEEE