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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Continuous wavefront sensing on future space telescopes allows relaxation ofstability requirements while still allowing on-orbit diffraction-limitedoptical performance. We consider the suitability of phase retrieval tocontinuously reconstruct the phase of a wavefront from on-orbit irradiancemeasurements or point spread function (PSF) images. As phase retrievalalgorithms do not require reference optics or complicated calibrations, it is apreferable technique for space observatories, such as the Hubble SpaceTelescope or the James Webb Space Telescope. To increase the robustness anddynamic range of the phase retrieval algorithm, multiple PSF images with knownamount of defocus can be utilized. In this study, we describe a recentlyconstructed testbed including a 97 actuator deformable mirror, changeableentrance pupil stops, and a light source. The aligned system wavefront error isbelow ~30nm. We applied various methods to generate a known wavefront error,such as defocus and/or other aberrations, and found the accuracy and precisionof the root mean squared error of the reconstructed wavefronts to be less than~10nm and ~2nm, respectively. Further, we discuss the signal-to-noise ratiosrequired for continuous dynamic wavefront sensing. We also simulate the case ofspacecraft drifting and verify the performance of the phase retrieval algorithmfor continuous wavefront sensing in the presence of realistic disturbances.

Focus diverse phase retrieval testbed development of continuous wavefront sensing for space telescope applications