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A Hybrid Lyot Coronagraph for the Direct Imaging and Spectroscopy of Exoplanet Systems: Recent Results and ProspectsWe report our best laboratory contrast demonstrations achieved to date. We review the design, fabrication, performance, and future prospects of a hybrid focal plane occulter for exoplanet coronagraphy. Composed of thickness-profiled metallic and dielectric thin films vacuum deposited on a fused silica substrate, the hybrid occulter uses two superimposed thin films for control over both the real and imaginary parts of the complex attenuation pattern. Together with a deformable mirror for adjustment of wavefront phase, the hybrid Lyot coronagraph potentially exceeds billion-to one contrast over dark fields extending to within angular separations of 3 lambda/D (3 x the cosmological constant / diameter of the telescope) from the central star, over spectral bandwidths of 20 percent or more, and with throughput efficiencies up to 60 percent. We report laboratory contrasts of 3 x 10 (sup -10) degrees over 2 percent bandwidths, 6 x 10 (sup -10) degrees over 10 percent bandwidths, and 2 x 10 (sup -9) over 20 percent bandwidths, achieved across high contrast fields extending from an inner working angle of 3 lambda/D to a radius of 15 lambda/D. Occulter performance is analyzed in light of recent experiments and optical models, and prospects for further improvements are summarized. The science capabilities of the hybrid Lyot coronagraph are compared with requirements of the ACCESS mission, a representative exoplanet space telescope concept study for the direct imaging and spectroscopy of exoplanet systems. This work has been supported by NASA's Technology Demonstration for Exoplanet Missions (TDEM) program.
Document ID
20150006063
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Trauger, John
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Moody, Dwight
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Gordon, Brian
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Krist, John
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Mawet, Dimitri
(European Southern Observatory Santiago, Chile)
Date Acquired
April 22, 2015
Publication Date
August 20, 2011
Subject Category
Instrumentation And Photography
Lunar And Planetary Science And Exploration
Astronomy
Meeting Information
Meeting: SPIE Optics + Photonics 2011
Location: San Diego, CA
Country: United States
Start Date: August 20, 2011
End Date: August 25, 2011
Sponsors: International Society for Optical Engineering
Distribution Limits
Public
Copyright
Other
Keywords
coronagraph
active optics
expolanet

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