Laboratory demonstration of 10-10 contrast at the inner working angle of a sub-scale starshade
Abstract
Starshades are a leading technology to enable the direct detection and spectroscopic characterization of Earth-like exoplanets. Two critical starshade technologies, starlight suppression and optical model validation, are being advanced through sub-scale starshade demonstrations at the Princeton starshade testbed. We report on the successful completion of a technology milestone focused on the demonstration of optical performance at flight-required levels. We demonstrate 10-10 contrast at the inner working angle (IWA) of a starshade with a flight-like Fresnel number at multiple wavelengths spanning a 10% bandpass. The contrast at the IWA is limited by diffraction that is a result of the reduced scale of the experiment, but quickly improves to 2x10-11 beyond the IWA. To demonstrate our ability in detecting faint sources in the presence of the small-scale diffraction, we artificially inject sources into the experimental images and extract them with basic source extraction techniques. We also report on model validation experiments where starshades with intentional defects built into their design are tested and shown to be in agreement with model predictions. This work has advanced starshade technology by demonstrating we can design a starshade capable of producing scientifically useful contrast levels and that our models accurately predict the performance of the starshade in the presence of defects.
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23537310H