Stellar Interferometric Beam Combiners in the Context of Linear Optics Networks

The performance of ground based optical stellar interferometers suffers from various atmospheric as well as instrumental disturbances. The mathematical modeling of any kind of disturbances is essential in order to properly design an interferometric instrument and to get realistic estimates of its envisaged performance. One of the instrumental disturbances that has recently gained particular interest is changes to the polarization state of the incoming stellar light. Conventional methods of modeling polarization of light, such as, e.g., the Mueller calculus, are usually separate from or outside the context of interference. In this contribution I introduce to stellar interferometry a mathematical formalism that is commonly used in the field of optical Quantum Information Science. I show that this formalism allows an elegant and easy-to-use integral treatment of polarization and interference for any beam combination scheme based on linear optical elements. In order to illustrate the formalism I apply it exemplarily to the modeling of some existing beam combiner concepts.