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arXiv · 2308.14855

Deformable mirror-based pupil chopping for exoplanet imaging and adaptive optics

Javier Perez Soto·Cesar Laguna·Benjamin L. Gerard·Anne Dattilo·Vincent Chambouleyron·Rebecca Jensen-Clem
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Abstract

Due to turbulence in the atmosphere images taken from ground-based telescopes become distorted. With adaptive optics (AO) images can be given greater clarity allowing for better observations with existing telescopes and are essential for ground-based coronagraphic exoplanet imaging instruments. A disadvantage to many AO systems is that they use sensors that can not correct for non-common path aberrations. We have developed a new focal plane wavefront sensing technique to address this problem called deformable mirror (DM)-based pupil chopping. The process involves a coronagraphic or non-coronagraphic science image and a deformable mirror, which modulates the phase by applying a local tip/tilt every other frame which enables correcting for leftover aberrations in the wavefront after a conventional AO correction. We validate this technique with both simulations (for coronagraphic and non-coronagraphic images) and testing (for non-coronagraphic images) on UCSC's Santa Cruz Extreme AO Laboratory (SEAL) testbed. We demonstrate that with as low as 250 nm of DM stroke to apply the local tip/tilt this wavefront sensor is linear for low-order Zernike modes and enables real-time control, in principle up to kHz speeds to correct for residual atmospheric turbulence.

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Javier Perez Soto, Cesar Laguna, Benjamin L. Gerard, Anne Dattilo, Vincent Chambouleyron, Rebecca Jensen-Clem. 2023-08-28. Deformable mirror-based pupil chopping for exoplanet imaging and adaptive optics. https://arxiv.org/abs/2308.14855

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