A Demonstration of Wavefront Sensing and Mirror Phasing from the Image Domain

Abstract

In astronomy and microscopy, distortions in the wavefront affect the dynamic range of a high contrast imaging system. These aberrations are either imposed by a turbulent medium such as the atmosphere, by static or thermal aberrations in the optical path, or by imperfectly phased subapertures in a segmented mirror. Active and adaptive optics (AO), consisting of a wavefront sensor and a deformable mirror, are employed to address this problem. Nevertheless, the non-common-path between the wavefront sensor and the science camera leads to persistent quasi-static speckles that are difficult to calibrate and which impose a floor on the image contrast. In this paper we present the first experimental demonstration of a novel wavefront sensor requiring only a minor asymmetric obscuration of the pupil, using the science camera itself to detect high order wavefront errors from the speckle pattern produced. We apply this to correct errors imposed on a deformable microelectromechanical (MEMS) segmented mirror in a closed loop, restoring a high quality point spread function (PSF) and residual wavefront errors of order $\sim 10$ nm using 1600 nm light, from a starting point of $\sim 300$ nm in piston and $\sim 0.3$ mrad in tip-tilt. We recommend this as a method for measuring the non-common-path error in AO-equipped ground based telescopes, as well as as an approach to phasing difficult segmented mirrors such as on the \emph{James Webb Space Telescope} primary and as a future direction for extreme adaptive optics.

9 pages, 6 figures

Cited by in corpus (14)

• Fine cophasing of segmented aperture telescopes with ZELDA, a Zernike wavefront sensor in the diffraction-limited regime
• Calibration of the island effect: Experimental validation of closed-loop focal plane wavefront control on Subaru/SCExAO
• The self-coherent camera as a focal plane fine phasing sensor
• The Near Infrared Imager and Slitless Spectrograph for the James Webb Space Telescope -- IV. Aperture Masking Interferometry
• Focal-plane wavefront sensing with the vector Apodizing Phase Plate
• Comparing focal plane wavefront control techniques:\\Numerical simulations and laboratory experiments
• Closed-loop focal plane wavefront control with the SCExAO instrument
• James Webb Space Telescope Optical Simulation Testbed I: Overview and First Results
• Kernel Phase and Coronagraphy with Automatic Differentiation
• In-focus wavefront sensing using non-redundant mask-induced pupil diversity
• Phasing segmented telescopes via deep learning methods: application to a deployable CubeSat
• Kernel Phase and Kernel Amplitude in Fizeau Imaging
• Wavefront sensing from the image domain with the Oxford-SWIFT integral field spectrograph
• Analytical decomposition of Zernike and hexagonal modes over an hexagonal segmented optical aperture