A coronagraph system with unbalanced nulling interferometer: progress of optics and control method

Jun Nishikawa; Masahito Oya; Masaaki Horie; Kazuma Sato; Masao Fukase; Naoshi Murakami; Takayuki Kotani; Shiomi Kumagai; Motohide Tamura; Yosuke Tanaka; Takashi Kurokawa

doi:10.1117/12.2055636

2 August 2014 A coronagraph system with unbalanced nulling interferometer: progress of optics and control method

Jun Nishikawa, Masahito Oya, Masaaki Horie, Kazuma Sato, Masao Fukase, Naoshi Murakami, Takayuki Kotani, Shiomi Kumagai, Motohide Tamura, Yosuke Tanaka, Takashi Kurokawa

Author Affiliations +

Proceedings Volume 9143, Space Telescopes and Instrumentation 2014: Optical, Infrared, and Millimeter Wave; 91433A (2014) https://doi.org/10.1117/12.2055636
Event: SPIE Astronomical Telescopes + Instrumentation, 2014, Montréal, Quebec, Canada

Abstract

We have studied a coronagraph system with an unbalanced nulling interferometer (UNI). An important characteristic is a pre-reduction of the star light to 1/100 at the UNI stage which enables to enhance the final contrast. In other point of view, the UNI stage magnifies the wavefront aberrations, which lead us to compensate for the wavefront aberrations beyond the AO systems capabilities. It consists of the UNI, adaptive optics, and a coronagraph. In our experiments, we have observed the extra speckle reduction of better than 0.07 by the advantage of the UNI system. In order to obtain better contrast, we planned to reconstruct all of the optics, which use UNI with 4QPM, a coronagraph with 8OPM or VVM, a dual feedback control method, and a wavefront correction inside the UNI by an upstream AO.

Citation Download Citation

Jun Nishikawa, Masahito Oya, Masaaki Horie, Kazuma Sato, Masao Fukase, Naoshi Murakami, Takayuki Kotani, Shiomi Kumagai, Motohide Tamura, Yosuke Tanaka, and Takashi Kurokawa "A coronagraph system with unbalanced nulling interferometer: progress of optics and control method", Proc. SPIE 9143, Space Telescopes and Instrumentation 2014: Optical, Infrared, and Millimeter Wave, 91433A (2 August 2014); https://doi.org/10.1117/12.2055636

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