Implicit electric field conjugation: Data-driven focal plane control

Context. Direct imaging of Earth-like planets is one the main science cases for next generation extremely large telescopes. This very challenging due to star-planet contrast that has be overcome. Most current high-contrast instruments are limited in sensitivity at small angular separations non-common path aberrations (NCPA). The NCPA leak through corona-graph and create bright speckles limit on-sky therefore also post-processed contrast. Aims. We aim remove by active focal plane wavefront control using a data-driven approach. Methods. developed new approach dark hole creation maintenance does not require an instrument model. called implicit Electric Field Conjugation (iEFC) it can empirically calibrated. makes robust complex where optical models might difficult realize. Numerical simulations have been used explore performance iEFC different coronagraphs. method was validated on internal source Magellan Adaptive Optics extreme (MagAO-X) demonstrate iEFC’s real instrument. Results. experiments achieve deep below 10 −9 with several easily extended broadband measurements show bandwidth up 40% handled without problems. Lab MagAO-X showed gain factor light 20–200 narrowband light. A 5 × −8 achieved Phase Apodized Pupil Lyot Coronagraph 7.5 λ / D. Conclusions. demonstrated work numerical lab experiments. It calibrated valuable ground-based systems.