Evolving exosolar planet detection methods with lab experiments and integrated modeling: Ⅰ. Modeling

摘要

Recent studies of exosolar planet detection methods with a space-based visible light coronagraph have shown the feasibility of this approach. However, the telescope optical precision requirements are extremely demanding - a few Angstroms residual wavefront error - which is beyond current capabilities for large optical surfaces. Secondly, the coronagraph depends upon use of masks located at either the pupil or a focus to reject the starlight and image the exosolar planet. Effects of diffraction and light scatter place precision requirements mask manufacturing. To increase understanding and optimize performance of the coronagraph, laboratory experiments backed by end-to-end integrated models are used to project on-orbit performance. Of particular importance is the wavefront propagation through the optical system - from simple Fraunhaufer propagation to vector propagators taking into account 3D structures of the masks. Accurate models, which match test data are then used to evolve the initial coronagraph concepts for in-flight performance. In part Ⅰ, we discuss error sources and model development to meet mission goals. In part Ⅱ, a paper to be published at a future date, we compare lab experiment and expected residual error sources.