High-contrast imaging techniques are essential for future space missions aimed at directly detecting and characterizing exoplanets. We constructed a new testbed called the facility for coronagraphic elemental technologies (FACET) for the development of high-contrast imaging techniques. FACET has three optical paths (A, B, and C). Path A is used for developing focal-plane phase mask (FPM) coronagraphs. Currently, we have been developing photonic-crystal multi-layer phase masks for suppressing stellar light over a broad wavelength range. In path B, we demonstrate high-contrast observation combining FPM coronagraphs with a dark hole (DH) control technique. A spatial light modulator (SLM) is used as a wavefront control device. We are developing DH control techniques that take advantage of the large pixel format of the SLM. In path C, we demonstrate DH control for detecting exoplanets not only around single stars but also around binary-star systems. We install the SLM into the common-path visible nulling coronagraph to test the multiple-star DH control. We report details of FACET and recent progress of our activities at FACET. We have recently made significant progress with the demonstration of observation for a single star for which we achieved a monochromatic contrast of 2.9 × 10−9 at path C.
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