Abstract

In recent years, there has been an increasing interest in the fabrication of optical fibres with micrometer and nanometer order diameters. Such fibres can be produced by heating and pulling a single-mode optical fibre to a very small diameter, d, ensuring that the adiabatic criteria for lossless transmission are satisfied. By decreasing d to the submicron range, the taper transition transforms the local fundamental mode from a core mode in the untapered region to a cladding mode in the taper waist, giving rise to a guided mode with a significant evanescent field outside the tapered area of the fibre. Such tapered fibres have been shown to be particularly suited for atom optics experiments, such as modal interferometers, spectral filters and sensors. A novel approach to trapping and guiding neutral atoms has been proposed by Balykin et al. [1]. In contrast to optical waveguides with relatively large diameters, many theoretical and experimental aspects of tapered fibres have not been investigated thoroughly and this is essential in order to achieve goals such as those proposed in [1].

© 2007 IEEE