Near field raman imaging

Abstract

A tunable super-lens (TSL) for nanoscale optical sensing and imaging of bio-molecules and nano-manufacturing utilizes negative-index materials (NIMs) that operate in the visible or near infrared light. The NIMs can create a lens that will perform sub-wavelength imaging, enhanced resolution imaging, or flat lens imaging. This new TSL covers two different operation scales. For short distances between the object and its image, a near-field super-lens (NFSL) can create or enhance images of objects located at distances much less than the wavelength of light. For the far-zone, negative values are necessary for both the permittivity ∈ a permeability μ. While well-structured periodic meta-materials, which require delicate design and precise fabrication, can be used, metal-dielectric composites are also candidates for NIMs in the optical range. The negative-refraction in the composite films can be made by using frequency-selective photomodification.