2017/03/13 by Kelsey Miller, Olivier Guyon, Miller, Kelsey +3 · 1 citation
Engineering · Physics and Astronomy · #Adaptive optics and wavefront sensing #Advanced X-ray Imaging Techniques #Digital Holography and Microscopy #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Optical Polarization and Ellipsometry #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.1703.04259
openalex publication_date 2017/03/13 · openalex created_date 2022/08/06 · openalex updated_date 2026/07/28
Direct imaging of exoplanets requires establishing and maintaining a high\ncontrast dark field (DF) within the science image to a high degree of precision\n(10-10). Current approaches aimed at establishing the DF, such as electric\nfield conjugation (EFC), have been demonstrated in the lab and have proven\ncapable of high contrast DF generation. The same approaches have been\nconsidered for the maintenance of the DF as well. However, these methods rely\non phase diversity measurements which require field modulation; this interrupts\nthe DF and consequently competes with the science acquisition. In this paper,\nwe introduce and demonstrate spatial linear dark field control (LDFC) as an\nalternative technique by which the high contrast DF can be maintained without\nmodulation. Once the DF has been established by conventional EFC, spatial LDFC\nlocks the high contrast state of the DF by operating a closed-loop around the\nlinear response of the bright field (BF) to wavefront variations that modify\nboth the BF and the DF. We describe here the fundamental operating principles\nof spatial LDFC and provide numerical simulations of its operation as a DF\nstabilization technique that is capable of wavefront correction within the DF\nwithout interrupting science acquisition.\n