Vector vortex coronagraph: first results in the visible
Abstract
We report the status of JPL and JDSU ongoing technological developments and contrast results of the vector vortex coronagraph (VVC) made out of liquid crystal polymers (LCP). The first topological charge 4 VVC was tested on the high contrast imaging testbed (HCIT) around 800 nm, under vacuum and with active wavefront control (32x32 Xinetics deformable mirror). We measured the inner working angle or IWA (50% off-axis transmission) at ~ 1.8λ/d. A one-sided dark hole ranging from 3λ/d to 10λ/d was created in polarized light, showing a mean contrast of ~ 2 × 10^(-7) over a 10% bandwidth. This contrast was maintained very close in (3 λ/d) in a reduced 2% bandwidth. These tests begin to demonstrate the potential of the LCP technology in the most demanding application of a space-based telescope dedicated to extrasolar planet characterization. The main limitations were identified as coming from incoherent sources such as multiple reflections, and residual chromaticity. A second generation of improved masks tackling these issues is being manufactured and will be tested on the HCIT in the coming months.
Additional Information
© 2009 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). D. M. is supported by an appointment to the NASA Postdoctoral Program at the Jet Propulsion Laboratory, California Institute of Technology, administered by Oak Ridge Associated Universities through a contract with NASA.Attached Files
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Additional details
- Eprint ID
- 57724
- Resolver ID
- CaltechAUTHORS:20150520-151419415
- NASA/JPL/Caltech
- NASA Postdoctoral Program
- Created
-
2015-05-20Created from EPrint's datestamp field
- Updated
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2023-03-16Created from EPrint's last_modified field
- Series Name
- Proceedings of SPIE
- Series Volume or Issue Number
- 7440