Abstract

To suppress starlight for direct exoplanet observation, we propose a common-path achromatic rotational-shearing coronagraph (CP-ARC), which is an interferocoronagraph with an angular-adjustable field rotator. The CP-ARC aims to maintain unwanted detection of stellar light, which can be suppressed incompletely by interference because of the finite diameter of the star. Compared to the previous interferocoronagraph, which had a nonadjustable $\mathrm{180}\mathrm{°}$ field rotation, the proposed CP-ARC can improve the coronagraphic contrast by several orders if the CP-ARC is combined with medium or large telescopes where the companion-star separation is optically resolved by more than a few Airy radii. The CP-ARC is made robust against mechanical disturbances due to the common-path interferometer principle.

© 2011 Optical Society of America

Achromatic interfero-coronagraph with two common-path interferometers in tandem

Alexander V. Tavrov, Jun Nishikawa, Motohide Tamura, Lyu Abe, Kaito Yokochi, Takashi Kurokawa, and Mitsuo Takeda
Appl. Opt. 47(27) 4915-4926 (2008)

Common-path achromatic interferometer–coronagraph: nulling of polychromatic light

Alexander V. Tavrov, Yosuke Kobayashi, Yosuke Tanaka, Tatsutoshi Shioda, Yukitoshi Otani, Takashi Kurokawa, and Mitsuo Takeda
Opt. Lett. 30(17) 2224-2226 (2005)

Common-path achromatic interferometer-coronagraph: images from a breadboard demonstrator

Alexander V. Tavrov, Jun Nishikawa, Motohide Tamura, Lyu Abe, Kaito Yokochi, Takashi Kurokawa, and Mitsuo Takeda
Appl. Opt. 46(28) 6885-6895 (2007)

Common-path lateral-shearing nulling interferometry with a Savart plate for exoplanet detection

Naoshi Murakami and Naoshi Baba
Opt. Lett. 35(18) 3003-3005 (2010)

Symmetric nulling coronagraph based on a rotational shearing interferometer

Deqing Ren and Eugene Serabyn
Appl. Opt. 44(33) 7070-7073 (2005)