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 (1.5-5.2λ/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.

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