The multiple-grating vector vortex coronagraph (Conference Presentation)

Frans Snik; David Doelman; Steven Bos; Mireille Ouellet; Michael Escuti; Garreth Ruane

doi:10.1117/12.2529554

9 September 2019 The multiple-grating vector vortex coronagraph (Conference Presentation)

Frans Snik, David Doelman, Steven Bos, Mireille Ouellet, Michael Escuti, Garreth Ruane

Proceedings Volume 11117, Techniques and Instrumentation for Detection of Exoplanets IX; 1111713 (2019) https://doi.org/10.1117/12.2529554
Event: SPIE Optical Engineering + Applications, 2019, San Diego, California, United States

Abstract

The contrast/bandwidth performance for current implementations of the Vector Vortex Coronagraph (VVC) is degraded by a leakage term that emerges when the optic does not exhibit a retardance of exactly half-wave. We present a novel implementation for the VVC that significantly rejects the polarization leakage term through diffraction. The optic consists of multiple separate layers of patterned liquid crystals, for which each extra layer adds two orders of magnitude of leakage rejection. The first layer combines a vortex pattern and a polarization grating into a so-called forked grating that splits the circular polarization states. Consecutive polarization gratings effectively cancel the first grating with full diffraction direction efficiency, resulting in a regular vortex phase with minimized leakage of the non-coronagraphic PSF. We present the designs and performance of double-grating VVC for the ground-based instruments VLT/SPHERE and Subaru/SCExAO, that instantaneously cover 1-2.5 um. In addition, we introduce the triple-grating VVC that fulfills the stringent requirements for technology demonstration towards high-contrast imaging at ~1E-10 levels with future space telescopes like the HabEx and LUVOIR mission concepts.

Conference Presentation

Citation Download Citation

Frans Snik, David Doelman, Steven Bos, Mireille Ouellet, Michael Escuti, and Garreth Ruane "The multiple-grating vector vortex coronagraph (Conference Presentation)", Proc. SPIE 11117, Techniques and Instrumentation for Detection of Exoplanets IX, 1111713 (9 September 2019); https://doi.org/10.1117/12.2529554

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
PRESENTATION

WATCH
PRESENTATION SAVE TO MY LIBRARY

GET CITATION

KEYWORDS

Coronagraphy

Diffraction gratings

Polarization

Diffraction

Liquid crystals

Point spread functions

Space telescopes

Keywords/Phrases

Search In:

Publication Years