Far-field characterization of ordered arrays of subwavelength apertures with adjustable dimensions

Abstract

Ordered arrays of nanometer-sized optical probes were developed on the distal face of coherent optical fiber bundles. The fabrication steps derived from SNOM probes methodology and allowed to produce high-density microarrays of nanoapertures with adjustable dimensions. The angular profile of the far-field intensity transmitted through the nanostructured arrays shows a diffracting behavior which is a function of the nanoaperture sizes. Nearfield optical behavior was thus established in an array format where each element is equivalent to a single nanoaperture. It means that each subwavelength aperture of the array is optically independent in the far-field regime. This analysis demonstrates its potential use as a near-field optical array. Since the initial architecture of the bundle is retained, the array format allows imaging a sample concomitantly at both nanometric and micrometric scales. Therefore such an array plays a bridging role between these 2 fundamental scales.