Effective cross sections for stray light calculations in laser interferometry: application to LISA science interferometer

This work describes a method used to calculate the amount of stray light able to couple to the detectors and create disturbing interference on the measurements in an arbitrarily complex optical system. The method is able to take into account the physical properties (diffraction) of the propagating beams and to translate them into geometrical considerations to calculate the stray light directions that arrive to influence the measurements. The system is in this work applied to the telescope of LISA instrument, that will be used to intercept gravitational waves in space. The method is a fast alternative to optical design softwares to have stray light estimates.