Selective dual-band subwavelength-holearrays-based polariser

The design and measurement of a novel dual-band polariser for millimetre-waves based on cavity effects and extraordinary transmission resonance is presented in this paper. A further analysis of a linear extraordinary transmission polariser recently proposed and its stack suggests the feasibility of designing different polarisation responses by changing the orientation of the middle wafer in a 3-wafers-stack. The measurements have been recorded by an AB-Millimetre^™ Quasi-optical Vector Network Analyzer under Fresnel illumination and a vertical dual-band polariser is achieved by a configuration of three wafers in which the central one has been rotated 90°. This result should find application in the design of new generation of polarising miniaturised devices, not only in the sub-terahertz range, but also in the optical regime.