Subwavelength colour imaging with a metallic nanolens

Early research into metamaterials by other scientists has shown that nanostructured metamaterials can focus incident light and act as a lens. Although such structures are capable of subwavelength imaging, they have two major restrictions: they can only work at one particular wavelength, and the image can only be transferred for a short distance within the limits of the near field and is therefore undetectable in the far field. Here, we propose a lens made of stacked silver nanorods that is capable of colour imaging at subwavelength resolution in the visible range. The subwavelength image can be transferred over distances of at least micrometre scale and magnified before detection by conventional optics devices. Such a nanorod lens has the potential to be an indispensable imaging tool, with particular application to biomedical applications, where individual viruses and other nano-entities could be imaged in colour in the far field.