Subwavelength focusing in the infrared range using a meta surface

This paper shows how a structure of a single subwavelength aperture surrounded by a finite number of gratings can be used to achieve subwavelength focusing of the infrared electromagnetic radiation. We use copper as a material which is CMOS compatible. The structure focuses the infrared incident radiation into a hot-spot of full width at half maximum (FWHM) smaller than the wavelength of the incident wave. This work opens up the possibility of many potential applications in the infrared range such as infrared miniaturized spectrometers, biosensors and the analysis of material properties and their chemical composition.