The vortex fiber nulling mode of the Keck Planet Imager and Characterizer (KPIC)

Abstract

The Keck Planet Imager and Characterizer (KPIC) is an upgrade to the Keck II adaptive optics system that includes an active fiber injection unit (FIU) for efficiently routing light from exoplanets to NIRSPEC, a high-resolution spectrograph. Towards the end of 2019, we will add a suite of new coronagraph modes as well as a high-order deformable mirror. One of these modes, operating in $K$-band (2.2$\mu m$), will be the first vortex fiber nuller to go on sky. Vortex Fiber Nulling (VFN) is a new interferometric method for suppressing starlight in order to spectroscopically characterize exoplanets at angular separations that are inaccessible with conventional coronagraph systems. A monochromatic starlight suppression of $6\times 10^{-5}$ in 635 nm laser light has already been demonstrated on a VFN testbed in the lab. A polychromatic experiment is now underway and coupling efficiencies of $<5\times 10^{-4}$ and $\sim 5\%$ have been demonstrated for the star and planet respectively in 10% bandwidth light. Here we describe those experiments, the new KPIC VFN mode, and the expected performance of this mode using realistic parameters determined from on-sky tests done during the KPIC commissioning.

arXiv comment11 pages; 7 figures; to appear in Proceedings of the SPIE, Techniques and Instrumentation for Detection of Exoplanets IX, Vol. 11117

References in corpus (8)

• Theoretical Limits on Extrasolar Terrestrial Planet Detection with Coronagraphs
• Observing Exoplanets with High Dispersion Coronagraphy. I. The scientific potential of current and next-generation large ground and space telescopes
• Observing Exoplanets with High-Dispersion Coronagraphy. II. Demonstration of an Active Single-Mode Fiber Injection Unit
• Efficient injection from large telescopes into single-mode fibres: Enabling the era of ultra-precision astronomy
• Efficient spectroscopy of exoplanets at small angular separations with vortex fiber nulling
• Nulling at short wavelengths: theoretical performance constraints and a demonstration of faint companion detection inside the diffraction limit with a rotating-baseline interferometer
• Vortex fiber nulling for exoplanet observations. I. Experimental demonstration in monochromatic light
• The Keck Planet Imager and Characterizer: Demonstrating advanced exoplanet characterization techniques for future extremely large telescopes

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• Vortex Fiber Nulling for Exoplanet Observations: Implementation and First Light
• Technical description and performance of the phase II version of the Keck Planet Imager and Characterizer
• Fringing analysis and forward modeling of Keck Planet Imager and Characterizer (KPIC) spectra
• Broadband vortex fiber nulling: high-dispersion exoplanet science at the diffraction limit
• Enhanced high-dispersion coronagraphy with KPIC phase II: design, assembly and status of sub-modules
• An Atmospheric Dispersion Corrector Design with Milliarcsecond-Level Precision from 1 to 4 microns for High Dispersion Coronagraphy