Abstract. In this paper we consider the propagation of waves in an open waveguide in the half space Formula: see text under Dirichlet- or Neumann boundary condition for Formula: see text. The index of refraction Formula: see text is periodic along the axis of the waveguide (which we choose to be the Formula: see textaxis) and equal to one for Formula: see text for some Formula: see text. Based on a limiting absorption principle, derived in a former paper, we formulate a radiation condition, prove existence and uniqueness of a solution and describe explicitely the asymptotic behavior along the axis of the waveguide. This behavior depends crucially on the existence of nonevanescent (normal to the axis of the waveguide) modes.
Andreas Kirsch (Mon,) studied this question.