Concept validation of a high dynamic range point-diffraction interferometer for wavefront sensing in adaptive optics

Dubost, Nicolás; Bharmal, Nazim Ali; Dubbeldam, Marc; 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. To achieve this, the pupil-modulated point-diffraction interferometer (m-PDI) was presented in an earlier paper. This present paper focuses on m-PDI concept validation through three experiments. First, the instrument’s accuracy and dynamic range are characterized by measuring the spatial transfer function at all spatial frequencies and at different amplitudes. Then, using visible monochromatic light, an AO control loop is closed on the system’s systematic bias to test for precision and completeness. In a central section of the pupil with 72% of the total radius, the residual error is 7.7 nm rms. Finally, the control loop is run using polychromatic light with a spectral FWHM of 77 nm around the R-band. The control loop shows no drop in performance with respect to the monochromatic case, reaching a final Strehl ratio larger than 0.7.

Citation

Dubost, N., Bharmal, N. A., Dubbeldam, M., & Myers, R. M. (2022). Concept validation of a high dynamic range point-diffraction interferometer for wavefront sensing in adaptive optics. Applied Optics, 61(14), 4160-4167. https://doi.org/10.1364/ao.439569

• Journal Article Type: Article
• Acceptance Date: Mar 30, 2022
• Online Publication Date: May 9, 2022
• Publication Date: 2022
• Deposit Date: May 10, 2022
• Publicly Available Date: Jul 19, 2022
• Journal: Applied Optics
• Print ISSN: 1559-128X
• Electronic ISSN: 2155-3165
• Publisher: Optica
• Peer Reviewed: Peer Reviewed
• Volume: 61
• Issue: 14
• Pages: 4160-4167
• DOI: https://doi.org/10.1364/ao.439569
• Public URL: https://durham-repository.worktribe.com/output/1208589