Interferometry beam combiners that use optical waveguides, i.e. optical fibers or integrated optics, become popular in optical interferometry because of their flexibility, but also in the case of single-mode waveguide because of their properties of spatial filtering that increases the accuracy of interferometric measurement in an atmosphere-perturbed environment. However we know very little
about the way the electric field propagates and even less about the
correlation between the different beams of an optical interferometer. In this paper, we present in this paper an analysis of single mode optical waveguides in the framework of stellar interferometry. We first analyze the output electric field using
radiated modes and show that the rejection rate we can derive in the
case of nulling interferometry depends on many parameters, including the flux integration radius and the force of the aberrations. Secondly, since the interferometric equation can be interpreted in terms of carrying wave that carries respectively the optical power received by each telescope and the coherent power between two telescopes, we show that the interferometric equation involves a quantity called the modal visibilities which is not equal to the object visibility. The relationship between the two visibilities and the behaviour in the presence of atmosphere are also presented.