Complete characterization of a high-numerical-aperture small-core fiber with subwavelength resolution using atomic force microscopy and near-field scanning optical microscopy

Abstract

The properties of a small-core high-numerical-aperture fiber are investigated using near-field scanning optical microscopy (NSOM). The microscopic structure of the fiber is also determined using a combination of etching and atomic force microscopy (AFM). Although the mode profile cannot be precisely predicted using AFM data alone, the measured profile is in extremely good agreement with that calculated using dimensional information provided by AFM and preform index data. © 2003 Society of Photo-Optical Instrumentation Engineers.