Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - FALCONER (Forging Advanced Liquid-Crystal Coronagraphs Optimized for Novel Exoplanet Research)

Teaser

In the ERC StG project FALCONER we develop novel coronagraphic components and optical systems based on patterned liquid-crystal technology. We aim to enable direct imaging of exoplanets, and moreover the characterization of the atmospheres of exoplanets through spectroscopy...

Summary

In the ERC StG project FALCONER we develop novel coronagraphic components and optical systems based on patterned liquid-crystal technology. We aim to enable direct imaging of exoplanets, and moreover the characterization of the atmospheres of exoplanets through spectroscopy and polarimetry. We mainly focus on the so-called vector-APP coronagraph, which is a pupil-plane phase mask that delivers two complementary point-spread functions with dark holes in which exoplanets can be observed. During this project, we design, test, and implement new coronagraphic masks with unprecedented contrast performance over large spectral bandwidths. In addition, we aim to optimize the entire optimal system by integrating the coronagraphic functionality with focal-plane wavefront sensing, (integral-field) spectroscopy, and dual-beam polarimetry. We install these coronagraphs at several of the largest ground-based telescopes, and apply them to search for hitherto unknown exoplanets, and (spectroscopically and polarimetric) characterize the atmospheres of known exoplanets.

Work performed

\"So far, we have successfully developed vector-APP coronagraphs covering a large range of wavelengths from 500 nm to 5 um, for Magallan/MagAO, LBT/LMIRcam, WHT/LExI, Subaru/SCExAO, Magallan/MagAO-X, VLT/ERIS, and the balloon experiment HiCIBaS. We have designed vector-APP coronagraphs for VLT/SPHERE upgrade, MMT/MMTpol, ELT/MICADO and ELT/METIS. We are currently validating the on-sky performance at LBT and Subaru, and are preparing for scientific harvesting.
We have invented a number of novel optical techniques for high-contrast imaging: the multiple-grating technique to suppress leakage light in vector-APP and Vector Vortex Coronagraphs by orders of magnitude, the vector-Zernike wavefront sensor that simultaneously measures phase and amplitude aberrations, and \"\"Holographic Amplitude Masking\"\" that offers multiplexed spectroscopic interferometry.
With existing instruments (VLT/SPHERE and VLT/NaCo) we have set out to measure the infrared polarization of companions (indicating, e.g., structured clouds), which has led to the first detection (CS Cha b), and upper limits for the HR8799 planets.\"

Final results

With our armada of vector-APP coronagraphs around the world, covering vis+IR wavelengths and northern+southern hemispheres, we will observe stellar companions, both to validate the on-sky performance, as well as to provide unique spectroscopic and polarimetric characterization.