Calibration of quasi-static aberrations in high-contrast astronomical adaptive optics with a pupil-modulated point-diffraction interferometer

Dubost, Nicolas; Bharmal, Nazim; Myers, Richard M.

Abstract

The direct detection and imaging of exoplanets requires the use of high-contrast adaptive optics (AO). In these systems quasi-static aberrations need to be highly corrected and calibrated. In order to achieve this, a high-sensitivity wavefront sensor, the pupil-modulated point-diffraction interferometer (m-PDI), is presented. This sensor modulates and retrieves both the phase and the amplitude of an incoming electric field. The theory behind the wavefront reconstruction, the visibility of fringes, chromatic effects and noise propagation are developed. Results show this interferometer has a wide chromatic bandwidth. For a bandwidth of ∆λ = 50% in units of central wavelength, the visibility of fringes and the response of the WFS to low and high-order aberrations are almost unaffected with respect to the monochromatic case. The WFS is, in contrast, very sensitive to variations in the size of its pinhole. The size of the pinhole is shown to affect the sensor’s linearity, the dynamic range and the amount of noise. Larger pinholes make the sensor less sensitive to low-order aberrations, but in turn also decrease the effects of misalignments.

Citation

Dubost, N., Bharmal, N., & Myers, R. M. (2018). Calibration of quasi-static aberrations in high-contrast astronomical adaptive optics with a pupil-modulated point-diffraction interferometer. Optics Express, 26(9), 11068-11083. https://doi.org/10.1364/oe.26.011068

• Journal Article Type: Article
• Acceptance Date: Apr 13, 2018
• Online Publication Date: Apr 16, 2018
• Publication Date: Apr 16, 2018
• Deposit Date: Apr 13, 2018
• Publicly Available Date: Apr 16, 2018
• Journal: Optics Express
• Electronic ISSN: 1094-4087
• Publisher: Optica
• Peer Reviewed: Peer Reviewed
• Volume: 26
• Issue: 9
• Pages: 11068-11083
• DOI: https://doi.org/10.1364/oe.26.011068
• Public URL: https://durham-repository.worktribe.com/output/1334075