First on-sky demonstration of spatial Linear Dark Field Control with the vector-Apodizing Phase Plate at Subaru/SCExAO

One of the key noise sources that currently limits high-contrast imaging observations for exoplanet detection is quasi-static speckles. Quasi-static speckles originate from slowly evolving non-common path aberrations (NCPA). The purpose this work to present a proof-of-concept on-sky demonstration spatial Linear Dark Field Control (LDFC). ultimate goal LDFC stabilize point spread function (PSF) by addressing NCPA using science image as additional wavefront sensor. We combined with Asymmetric Pupil vector-Apodizing Phase Plate (APvAPP) on Subaru Coronagraphic Extreme Adaptive Optics system at Telescope. In paper, we report results first successful proof-of-principle tests. two types cases: (1) correction instrumental errors and atmospheric residuals plus artificially induced static introduced deformable mirror (2) only aberrations. When introducing artificial DM, find can improve raw contrast factor $3$--$7$ over dark hole. these tests, residual error decreased $\sim$50 nm RMS, $\sim$90 $\sim40$ RMS. case aberrations, show able suppress have timescales $<0.1$--$0.4$ Hz. power $10^{-2}$ Hz reduced $\sim$20, 7, 4 frequency bins 2.5, 5.5, 8.5 $\lambda/D$, respectively. presented in promising technique enabling goals upcoming generation extremely large telescopes.