Stellar Coronagraph Performance Impact due to Particulate Contamination and Scatter

摘要

The detection and characterization of earth-like exo-planets with space coronagraph instruments could be adversely affected by contamination of the many optical surfaces from the telescope primary mirror to the coronagraph mask. Particulate contamination that may accumulate even in clean room conditions over the period of integration, testing, and launch can cause performance degradation due to both coherent and incoherent scatter. While the coherent components can be compensated in broad-band light using a sequential deformable mirror architecture, incoherent scatter would remain. We show the challenges and effects of particulate contamination based on measurements and estimates, and discuss the requirements throughout the coronagraph system while accounting for the wavefront control system.