  Atoms coupled to optical fields confined in one and two spatial dimensions in
solid state microstructures can experience very large light shifts if the
driving frequencies are close to a resonance of the microstructures and an
atomic transition. Using the simple example of a quasi one-dimensional
waveguide structure we can analytically calculate the atomic AC Stark shift and
the modifications of the light field induced by the presence of the atom. A
large enhancement of the effective interaction strength is found due to a non
uniform mode density. Experimentally this should be visible by monitoring the
scattered light field as well as by the modification of the atomic trajectories
bouncing from the evanescent light.
