Laboratory Demonstration of Spatial Linear Dark Field Control For Imaging Extrasolar Planets in Reflected Light
Year: 2020
Type: article
Abstract: Imaging planets in reflected light, a key focus of future NASA missions and extremely large telescopes, requires advanced wavefront control to maintain a deep, temporally correlated null of stellar halo—i.e., a dark hole (DH)—at just several diffraction beam widths. Using the Ames Coronagraph Experiment testbed, we present the first laboratory tests of Spatial Linear Dark Field Control (LDFC) approaching raw contrasts (∼5 × 10 −7 ) and separations (1.5–5.2 λ / D ) needed to image Jovian planets around Sun-like stars with space-borne coronagraphs like WFIRST-CGI and image exo-Earths around low-mass stars with future ground-based 30 m class telescopes. In four separate experiments and for a range of different perturbations, LDFC largely restores (to within a factor of 1.2–1.7) and maintains a DH whose contrast is degraded by phase errors by an order of magnitude. Our implementation of classical speckle nulling requires a factor of 2–5 more iterations and 20–50 deformable mirror (DM) commands to reach contrasts obtained by spatial LDFC. Our results provide a promising path forward to maintaining DHs without relying on DM probing and in the low-flux regime, which may improve the duty cycle of high-contrast imaging instruments, increase the temporal correlation of speckles, and thus enhance our ability to image true solar system analogues in the next two decades.
Authors: Thayne Currie, Eugene Pluzhnik, Olivier Guyon, Ruslan Belikov, Kelsey Miller, Steven Bos, Jared Males, Dan Sirbu, Charlotte Bond, Richard Frazin, Tyler Groff, Brian Kern, Julien Lozi, Benjamin A. Mazin, Bijan Nemati, Barnaby Norris, Hari Subedi, Scott Will
Institutions: Ames Research Center, Eureka Scientific, National Astronomical Observatory of Japan, Bay Area Environmental Research Institute, University of Arizona, Astrobiology Center, Leiden University, Leiden Observatory, University of Hawaii System, University of Hawaii at Hilo, University of Michigan, Goddard Space Flight Center, California Institute of Technology, Jet Propulsion Laboratory, University of California, Santa Barbara, The University of Sydney, Princeton University, University of Rochester
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Award: G2326699893
OpenAlex ID: W3045923095