title: Common-path achromatic rotational-shearing coronagraph.
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 180° 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.
authors.affiliation: Space Research Institute of RAS, Profsoyuznaya Ulitsa 84/32, Moscow 117997, Russia. tavrov@iki.rssi.ru
authors.forename: Alexander
authors.initials: A
authors.lastname: Tavrov
authors.forename: Oleg
authors.initials: O
authors.lastname: Korablev
authors.forename: Leonid
authors.initials: L
authors.lastname: Ksanfomaliti
authors.forename: Alexander
authors.initials: A
authors.lastname: Rodin
authors.forename: Pavel
authors.initials: P
authors.lastname: Frolov
authors.forename: Jun
authors.initials: J
authors.lastname: Nishikwa
authors.forename: Motohide
authors.initials: M
authors.lastname: Tamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Kurokawa
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Takeda