Cheapest nuller in the world: Crossed beamsplitter cubes

Abstract

In this communication is described a new type of Achromatic phase shifter (APS) suitable for both nulling interferometry and coronagraphy, based on a couple of crossed beamsplitter cubes, well-suited for equipping future spaceborne instruments searching for extra-solar planets located in a habitable zone. We present the general principle of this APS and discuss possible implementations into a nulling coronagraph telescope or into a sparse-aperture interferometer, either of the Fizeau or Michelson type. Expected performance in terms of transmission maps and a preliminary tolerance analysis are also provided. It turns out that the device is cheap, compact, and presents reasonable manufacturing tolerances and costs

This paper has been withdrawn by the authors due to wrong phase-shifts of the beams transmitted by the semi-reflective cubes. It follows that an achromatic and non polarized null is only achievable with two of the four considered telescopes. A revised paper will be issued soon