Enhanced energy throughput in corrugated, tapered, metal-coated SNOM probes

摘要

Interest in optical devices that image with superresolution and inherent optical parallelism continues. Recently, the concept of superresolution is pursued along the lines of negative refraction and transparent multilayer, metallo-dielectric photonic band gap structures. Flat superlenses image from the near-field to the near- or far-field with resolution beyond the diffraction limit. There is a need for characterization methods which allow measurement of the point spread function of such devices. Scanning near-field microscopes (SNOMs) measure the field intensity in the vicinity of objects as close as 5 nm due to shear-force technique. Improvement of transversal resolution up to λ/20 may be possible due to considerable improvement of energy throughput of SNOM probes. To this aim we propose to corrugate the dielectric core-metal coating interface of SNOM probes. The corrugations facilitate the excitation of surface plasmons, which enhance the transport of energy to the probe aperture.