English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Future large segmented space telescopes and their coronagraphic instrumentsare expected to provide the resolution and sensitivity to observe Earth-likeplanets with a 10^10 contrast ratio at less than 100 mas from their host star.Advanced coronagraphs and wavefront control methods will enable the generationof high-contrast dark holes in the image of an observed star. However, driftsin the optical path of the system will lead to pointing errors and othercritical low-order aberrations that will prevent maintenance of this contrast.To measure and correct for these errors, we explore the use of a Zernikewavefront sensor (ZWFS) in the starlight rejected and filtered by the focalplane mask of a Lyot-type coronagraph. In our previous work, the analyticalphase reconstruction formalism of the ZWFS was adapted for a filtered beam. Wenow explore strategies to actively compensate for these drifts in a segmentedpupil setup on the High-contrast imager for Complex Aperture Telescopes(HiCAT). This contribution presents laboratory results from closed-loopcompensation of bench internal turbulence as well as known introducedaberrations using phase conjugation and interaction matrix approaches. We alsostudy the contrast recovery in the image plane dark hole when using a closedloop based on the ZWFS.

Experimental validation of active control of low-order aberrations with a Zernike sensor through a Lyot coronagraph