Enhanced optical near field from a bowtie aperture

Abstract

The enhanced optical near field from a bowtie aperture in an aluminum film is experimentally demonstrated using near-field scanning optical microscopy. The full width half magnitude near-field optical spot is determined to be about 65×34nm2 by 458nm argon ion laser illumination, which is seven times smaller than those obtained from square and rectangular apertures of the same opening area. Light concentration and transmission enhancement of bowtie apertures promise a highly efficient nanoscale light source for near-field optical applications.