Minimizing the polarization leakage of geometric-phase coronagraphs with multiple grating pattern combinations

Abstract

The design of liquid-crystal diffractive phase plate coronagraphs for ground-based and space-based high-contrast imaging systems is limited by the trade-off between spectral bandwidth and polarization leakage. We demonstrate that by combining phase patterns with a polarization grating (PG) pattern directly followed by one or several separate PGs, we can suppress the polarization leakage terms by additional orders of magnitude by diffracting them out of the beam. \textcolor{black}{Using two PGs composed of a single-layer liquid crystal structure in the lab, we demonstrate a leakage suppression of more than an order of magnitude over a bandwidth of 133 nm centered around 532 nm. At this center wavelength we measure a leakage suppression of three orders of magnitude.} Furthermore, simulations indicate that a combination of two multi-layered liquid-crystal PGs can suppress leakage to $<10^{-5}$ for 1-2.5 $\mu$m and $<10^{-10}$ for 650-800 nm. We introduce multi-grating solutions with three or more gratings that can be designed to have no separation of the two circular polarization states, and offer even deeper suppression of polarization leakage. We present simulations of a triple-grating solution that has $<10^{-10}$ leakage on the first Airy ring from 450 nm to 800 nm. We apply the double-grating concept to the Vector-Vortex coronagraph of charge 4, and demonstrate in the lab that polarization leakage no longer limits the on-axis suppression for ground-based contrast levels. Lastly, we report on the successful installation and first-light results of a double-grating vector Apodizing Phase Plate pupil-plane coronagraph installed at the Large Binocular Telescope. We discuss the implications of these new coronagraph architectures for high-contrast imaging systems on the ground and in space.

arXiv comment23 pages, 15 figures, accepted for publication in PASP

References in corpus (22)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Angular Differential Imaging: a Powerful High-Contrast Imaging Technique
• The Gemini Planet Imager: First Light
• SPHERE: the exoplanet imager for the Very Large Telescope
• Imaging Spectroscopy for Extrasolar Planet Detection
• Combining high-dispersion spectroscopy (HDS) with high contrast imaging (HCI): Probing rocky planets around our nearest neighbors
• Optical Vectorial Vortex Coronagraphs using Liquid Crystal Polymers: theory, manufacturing and laboratory demonstration
• The Vector Vortex Coronagraph: Laboratory Results and First Light at Palomar Observatory
• The Vector-APP: a Broadband Apodizing Phase Plate that yields Complementary PSFs
• The W. M. Keck Observatory infrared vortex coronagraph and a first image of HIP79124 B
• First On-Sky High Contrast Imaging with an Apodizing Phase Plate
• Laboratory demonstration of a mid-infrared AGPM vector vortex coronagraph
• On-sky performance analysis of the vector Apodizing Phase Plate coronagraph on MagAO/Clio2
• Performance characterization of a broadband vector Apodizing Phase Plate coronagraph
• Three years of harvest with the vector vortex coronagraph in the thermal infrared
• Advancing European High-Contrast Imaging R&D Towards the Habitable Worlds Observatory
• Optimizing the subwavelength grating of L-band Annular Groove Phase Masks for high coronagraphic performance
• SCExAO, an instrument with a dual purpose: perform cutting-edge science and develop new technologies
• Patterned liquid-crystal optics for broadband coronagraphy and wavefront sensing
• First Light with ALES: A 2-5 Micron Adaptive Optics Integral Field Spectrograph for the LBT
• Review of high-contrast imaging systems for current and future ground- and space-based telescopes I. Coronagraph design methods and optical performance metrics
• Vortex-phase filtering technique for extracting spatial information from unresolved sources

Cited by in corpus (14)

• The vector-apodizing phase plate coronagraph: design, current performance, and future development
• Imaging exoplanets with coronagraphic instruments
• Measuring the variability of directly imaged exoplanets using vector Apodizing Phase Plates combined with ground-based differential spectrophotometry
• First Images of the Protoplanetary Disk Around PDS 201
• High-contrast observations of brown dwarf companion HR 2562 B with the vector Apodizing Phase Plate coronagraph
• Exploring the directly imaged HD 1160 system through spectroscopic characterization and high-cadence variability monitoring
• High-Contrast Coronagraphy
• Applying a temporal systematics model to vector Apodizing Phase Plate coronagraphic data: TRAP4vAPP
• Vector speckle grid: instantaneous incoherent speckle grid for high-precision astrometry and photometry in high-contrast imaging
• First light of a holographic aperture mask: Observation at the Keck OSIRIS Imager
• Astronomy from the Moon: From Exoplanets to Cosmology in Visible Light and Beyond
• Chasing the storm: Investigating the application of high-contrast imaging techniques in producing precise exoplanet light curves
• Active rejection-enhancement of spectrally adaptive liquid crystal geometric phase vortex coronagraphs
• L-band Integral Field Spectroscopy of the HR 8799 Planetary System