A coronagraph system with unbalanced nulling interferometer: progress of dynamic range

Jun Nishikawa; Kaito Yokochi; Naoshi Murakami; Lyu Abe; Takayuki Kotani; Motohide Tamura; Takashi Kurokawa; Alexander V. Tavrov; Mitsuo Takeda; Hiroshi Murakami

doi:10.1117/12.925792

21 September 2012 A coronagraph system with unbalanced nulling interferometer: progress of dynamic range

Jun Nishikawa, Kaito Yokochi, Naoshi Murakami, Lyu Abe, Takayuki Kotani, Motohide Tamura, Takashi Kurokawa, Alexander V. Tavrov, Mitsuo Takeda, Hiroshi Murakami

Author Affiliations +

Proceedings Volume 8442, Space Telescopes and Instrumentation 2012: Optical, Infrared, and Millimeter Wave; 84425D (2012) https://doi.org/10.1117/12.925792
Event: SPIE Astronomical Telescopes + Instrumentation, 2012, Amsterdam, Netherlands

Abstract

We have studied a coronagraph system with an unbalanced nulling interferometer (UNI). It consists of the UNI, adaptive optics, and a coronagraph. An important characteristic is a magnification of the wavefront aberrations in the UNI stage, which enables us to compensate for the wavefront aberrations beyond the AO systems capabilities. In our experiments, we have observed the stable aberration magnification of about 6 times and compensation to about λ/100 rms corresponding to λ/600 rms virtually. As a result, at the final focal plane of a 3-dimensional Sagnac interferometric nulling coronagraph, we have obtained the extra speckle reduction of better than 0.07 by the advantage of the UNI-PAC system. In order to obtain better contrast, we consider improvement of the optics with an 8OPM coronagraph, a dual feedback control, an unbalanced nulling interferometer with 4QPM or VVM, and a wavefront correction inside the UNI.

Citation Download Citation

Jun Nishikawa, Kaito Yokochi, Naoshi Murakami, Lyu Abe, Takayuki Kotani, Motohide Tamura, Takashi Kurokawa, Alexander V. Tavrov, Mitsuo Takeda, and Hiroshi Murakami "A coronagraph system with unbalanced nulling interferometer: progress of dynamic range", Proc. SPIE 8442, Space Telescopes and Instrumentation 2012: Optical, Infrared, and Millimeter Wave, 84425D (21 September 2012); https://doi.org/10.1117/12.925792

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