Fabrication and application of near-field optical fibre probe

Abstract

In this paper, the fabrication of a large cone angle near-field optical fibre probe, using the two-step chemical etching method and bent probe, is introduced and the controlling parameters of the coated Cr-Al film at the probe tip are presented. The scanning electron microscopy images display that the tip diameter of the uncoated large cone angle fibre probe obtained is less than 50nm, the cone angle over 90° and the diameter of light aperture at the coated probe tip is less than 100nm. The measured results of the optical transmission efficiency for various probe tips show that the uncoated straight optical fibre probe, film-coated straight probe and film-coated bent probe are 3×10-1, 2×10-3 and 1×10-4 times that of the flat fibre probe, respectively. In addition, the force images and near-field optical images of a standard sample are acquired using a large cone angle and film-coated bent probe.