Experimental analysis of the achromatic performance of a vector vortex coronagraph
Abstract
The vector vortex coronagraph is an instrument designed for direct detection and spectroscopy of exoplanets over a broad spectral range. Our team is working towards demonstrating contrast performance commensurate with imaging temperate, terrestrial planets orbiting solar-type stars using the High Contrast Imaging Testbed facility at NASA's Jet Propulsion Laboratory. To date, the best broadband performance achieved is ~10⁻⁸ raw contrast over a bandwidth of Δλ/λ=10% in the visible regime (central wavelengths of 550 nm-750 nm), while monochromatic tests yield much deeper contrast (~10⁻⁹ or better). In this study, we analyze the main performance limitations on the testbeds so far, focusing on the quality of the focal plane mask manufacturing. We measure the polarization properties of the masks and the residual electric field in the dark hole as a function of wavelength. Our results suggest that the current performance is limited by localized defects in the in the focal plane masks. A new generation of masks is under test that have fewer defects and promise performance improvements.
Additional Information
© 2020 Society of Photo-Optical Instrumentation Engineers (SPIE). This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA).Attached Files
Published - 114432O.pdf
Submitted - 2012.07728.pdf
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Additional details
- Eprint ID
- 107385
- Resolver ID
- CaltechAUTHORS:20210108-145720027
- NASA/JPL/Caltech
- Created
-
2021-01-09Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Astronomy Department
- Series Name
- Proceedings of SPIE
- Series Volume or Issue Number
- 11443