The effect of the van der Waals interaction on the excited state for atom guiding in metal-coated, hollow-core optical fibers

Abstract

The study of atom guiding in a metal-coated, hollow-core optical fiber has been extended to the case of moderate to strong coherent excitation. Significant populations of the upper level are produced and the effect of the increased van der Waals interaction of the excited state with the inner wall is represented as a multiplicative scaling factor of the ground state interaction. This scaling factor is justified by a simple, exact calculation for atomic hydrogen where the van der Waals interaction for H(4p) is a factor of 400 larger than that for the H(1s). By combining the optical dipole potential and the population-weighted van der Waals level shifts, an overall guiding barrier is obtained. The barrier functions are maximized in terms of both the detuning and the radial position to give the maximum barrier heights. For given laser field strengths at the inner wall, the resulting barriers depend strongly on the van der Waals scaling factors.