Design of the Advanced Virgo non-degenerate recycling cavities

Advanced Virgo is the project to upgrade the interferometric gravitational wave detector Virgo, and it foresees the implementation of power and signal non-degenerate recycling cavities. Such cavities suppress the build-up of high order modes of the resonating sidebands, with some advantage for the commissioning of the detector and the build-up of the gravitational signal. Here we present the baseline design of the Advanced Virgo non-degenerate recycling cavities, giving some preliminay results of simulations about the tolerances of this design to astigmatism, mirror figure errors and thermal lensing.