Speaker
Description
Current high-contrast imaging instruments are limited by wavefront errors originating from non-common path aberrations due, for example, to manufacturing errors in the optics and temperature drifts in the system. These create quasi-static speckles in the final science image that are difficult to distinguish from companions. The Self-Coherent Camera (SCC) exploits the light incoherence between the star and its companion to sense the stellar speckle field on the focal plane. The starlight that hits the coronagraph focal plane mask is diffracted outside the Lyot stop and is spatially filtered by a pinhole to create a reference beam. The reference beam and the leaked starlight are recombined on the science plane, creating interference fringes that do not affect the companion. We have designed and manufactured the coronagraphic focal plane mask in-house at Leiden University with Nanoscribe, a micro-3D-printer that uses two-photon polymerization to achieve sub-micron precision in height and print smooth structures.
We present preliminary results of the first on-sky closed-loop demonstration of the Fast Atmospheric SCC Technique (FAST), a focal plane wavefront sensing and control technique using the SCC. This was performed with MagAO-X, the extreme adaptive optics instrument for the 6.5-meter Magellan Clay telescope at Las Campanas Observatory. The FAST can also be used in post-processing as a differential imaging technique to further enhance the contrast.
| Talk category | Splinter 1: Large Infrastructure and instrumentation |
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