  We examine the effect of a wiggly cosmic string for both massless and massive
particle propagation along the string axis. We show that the wave equation that
governs the propagation of a scalar field in the neighborhood of a wiggly
string is formally equivalent to the quantum wave equation describing the
hydrogen atom in two dimensions. We further show that the wiggly string
spacetime behaves as a gravitational waveguide in which the quantized wave
modes propagate with frequencies that depend on the mass, string energy
density, and string tension. We propose an analogy with an optical fiber,
defining an effective refractive index likely to mimic the cosmic string effect
in the laboratory.
