Spatial filtering efficiency of single-mode optical fibers for stellar interferometry applications: phenomenological and numerical study

This paper reports on numerical simulations of spatial filtering efficiency using optical fibers. The filtering capability of the waveguide is evaluated by launching a non-guided optical field and measuring the power rejection along the propagation, over a given integration area. The Beam Propagation Method (BPM) allows to compute the transverse field distribution all along the guide, whose refractive index profile has been defined beforehand. This work is restricted to the study of straight waveguides. Scaling rules are proposed as functions of operating wavelength and numerical apertures.