Field intensity distributions and polarization orientations in a vacuum-clad subwavelength-diameter optical fiber

We study the properties of the field in the fundamental mode HE11 of a vacuum-clad subwavelength-diameter optical fiber using the exact solutions of Maxwell's equations. We obtain simple analytical expressions for the total intensity of the electric field. We discuss the origin of the deviations of the exact fundamental mode HE11 from the approximate mode LP01. We show that the thin thickness of the fiber and the high contrast between the refractive indices of the silica core and the vacuum-clad substantially modify the intensity distributions and the polarization properties of the field and its components, especially in the vicinity of the fiber surface. One of the promising applications of the field around the subwavelength-diameter fiber is trapping and guiding of atoms by the optical force of the evanescent field. (C) 2004 Elsevier B.V. All rights reserved.