Far-field imaging of subwavelength scale object based on multi-channel metamaterials

Abstract

Subwavelength object imaging is fundamentally restricted by diffraction limit. The limitation is originated by evanescent wave which is essential for fine structure imaging. Negative index metamaterial with a grating shape has been studied to transfer decaying wave information beyond proximity, but aliasing effect between original wave and transformed decaying wave is unresolved. Distinguishability on diffracted light is a first priority when the wave information is detected. We demonstrate that an interweaving conductor metamaterial (ICM) is applied to transmit diffracted light separately without mixing. An analysis of image retrieval process is also performed concisely and accurately by transfer matrix inversion. To collect diffracted light at once, sampling expansion method is implemented by locating a sequence of small object. Finally, we show perfect image reconstruction of any subwavelength aperture which is expressed within 3 times free-space wave vector in simulation region.