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A family of subwave...
A family of subwavelength grating vortexcoronagraphs (SGVCs) with higher topological charge
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Delacroix, Christian (författare)
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- Forsberg, Pontus (författare)
- Uppsala universitet,Tillämpad materialvetenskap
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Piron, Pierre (författare)
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visa fler...
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Ruane, Garreth (författare)
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Huby, Elsa (författare)
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Carlomagno, Brunella (författare)
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Jolivet, Aïssa (författare)
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- Vargas Catalan, Ernesto (författare)
- Uppsala universitet,Tillämpad materialvetenskap
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Absil, Olivier (författare)
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Mawet, Dimitri (författare)
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- Karlsson, Mikael (författare)
- Uppsala universitet,Tillämpad materialvetenskap
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Surdej, Jean (författare)
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Habraken, Serge (författare)
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visa färre...
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(creator_code:org_t)
- SPIE, 2015
- 2015
- Engelska.
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Ingår i: Techniques and Instrumentation for Detection of Exoplanets VII. - : SPIE.
- Relaterad länk:
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https://www.spiedigi...
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visa fler...
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- The subwavelength grating vortex coronagraph (SGVC) is a focal-planespiral-like phase mask whose key benefit is to allow high contrast imaging atsmall angles. Directly etched onto a CVD diamond substrate, it is well suitedto perform in the mid-infrared domain. It provides a continuous helicalphase ramp with a dark singularity in its center, and is characterized by itsnumber of phase revolutions, called the topological charge. Over the pasttwo years, we have manufactured several charge-2 SGVCs (a.k.a. annulargroove phase masks) and successfully demonstrated their performanceson 10-m class telescopes (LBT, VLT/NaCo, VLT/VISIR). To prevent stellarleakage on future 30-m class telescopes (E-ELT, TMT, GMT), a broaderoff-axis extinction is required, which can be achieved by increasing thetopological charge. We have recently proposed an original design for acharge-4 SGVC allowing less starlight to leak through the coronagraph, atthe cost of a degraded inner working angle. In this talk, we report on ourlatest development of higher charge SGVCs. From 3D rigorous numericalsimulations using a finite-difference time-domain (FDTD) algorithm, weConference 9605: Techniques and Instrumentationfor Detection of Exoplanets VIIR eturn to Contents +1 360 676 3290 · help@spie.org 647have derived a family of coronagraphs with higher topological charge(SGVC4/6/8). Our new optimization method addresses the principallimitation of such space-variant polarization state manipulation, i.e., theinconvenient discontinuities in the discrete grating pattern. The resultinggratings offer improved precision to the phase modulation compared toprevious designs. Finally, we present our preliminary manufacturing andmetrology results for infrared components down to the K-band.
Ämnesord
- NATURVETENSKAP -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)
Publikations- och innehållstyp
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- Av författaren/redakt...
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Delacroix, Chris ...
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Forsberg, Pontus
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Piron, Pierre
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Ruane, Garreth
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Huby, Elsa
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Carlomagno, Brun ...
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visa fler...
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Jolivet, Aïssa
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Vargas Catalan, ...
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Absil, Olivier
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Mawet, Dimitri
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Karlsson, Mikael
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Surdej, Jean
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Habraken, Serge
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visa färre...
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Uppsala universitet