Laboratory testing of coronagraphs for future space telescopes on the Caltech high contrast spectroscopy testbed for segmented telescopes (HCST) (Conference Presentation)

Garreth Ruane; Dimitri Mawet; Jacques-Robert Delorme; Nemanja Jovanovic; Daniel Echeverri; Jorge D. Llop Sayson; Manxuan (Rebecca) Zhang; A. J. Eldorado Riggs; Stuart Shaklan; Eugene Serabyn; James K. Wallace

doi:10.1117/12.2312851

10 July 2018 Laboratory testing of coronagraphs for future space telescopes on the Caltech high contrast spectroscopy testbed for segmented telescopes (HCST) (Conference Presentation)

Garreth Ruane, Dimitri Mawet, Jacques-Robert Delorme, Nemanja Jovanovic, Daniel Echeverri, Jorge D. Llop Sayson, Manxuan (Rebecca) Zhang, A. J. Eldorado Riggs, Stuart Shaklan, Eugene Serabyn, James K. Wallace

Author Affiliations +

Proceedings Volume 10698, Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave; 106981F (2018) https://doi.org/10.1117/12.2312851
Event: SPIE Astronomical Telescopes + Instrumentation, 2018, Austin, Texas, United States

Abstract

Imaging Earth-like exoplanets with future space telescopes will require a coronagraph instrument that is capable of creating a dark zone in the starlight at the image plane that is ten orders of magnitude fainter than the off-axis image of the host star. What is more, the coronagraph must simultaneously provide a stable dark zone and high throughput over the angular separations that correspond to habitable zones around nearby Sun-like stars (~10-100 milliarcseconds). Since the pupils of most large-aperture space telescope architectures are likely to be obstructed by secondary mirrors, spider support structures, and gaps between mirror segments, the coronagraph optics must also be specially tailored to passively suppress starlight diffracted from the obstructions and discontinuities in the telescope pupil. Here, we demonstrate an apodized vortex coronagraph optimized for an off-axis segmented telescope on the new High Contrast Spectroscopy Testbed for Segmented Telescopes (HCST) at Caltech. The coronagraph consists of a microdot apodizer, a liquid crystal vortex phase mask in the focal plane, and a Lyot stop. The microdot apodizer is an AR-coated glass window with 10um gold microdots to be used in reflection around lambda=800nm. We describe the HCST optical system; the apodizer optimization, fabrication, and metrology procedures; and present end-to-end testbed results of the coronagraph coupled with a 32x32 Boston Micromachines deformable mirror for wavefront control. We aim to achieve a dark zone 10^-7 times fainter than the simulated host star over a wavelength range of 800±40nm in Spring 2018. Finally, we will outline future plans to demonstrate coronagraph concepts for centrally obscured telescopes.

Conference Presentation

Citation Download Citation

Garreth Ruane, Dimitri Mawet, Jacques-Robert Delorme, Nemanja Jovanovic, Daniel Echeverri, Jorge D. Llop Sayson, Manxuan (Rebecca) Zhang, A. J. Eldorado Riggs, Stuart Shaklan, Eugene Serabyn, and James K. Wallace "Laboratory testing of coronagraphs for future space telescopes on the Caltech high contrast spectroscopy testbed for segmented telescopes (HCST) (Conference Presentation)", Proc. SPIE 10698, Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave, 106981F (10 July 2018); https://doi.org/10.1117/12.2312851

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