Adaptive optics operation with focal wavefront sensor in a coronagraph for direct observation of exoplanets
Adaptive optics operation with focal wavefront sensor in a coronagraph for direct observation of exoplanets
复制标题
日冕仪中使用焦点波前传感器进行自适应光学操作，用于直接观察系外行星
DOI：
10.1117/12.2055670
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Takashi
中科院分区：
文献类型：
--
作者：
Oya;Masahito;Nishikawa;Jun;Horie;Masaaki;Sato;Kazuma;Fukase;Masao;Murakami;Naoshi;Kotani;Takayuki;Kumagai;Shiomi;Tamura;Motohide;Tanaka;Yosuke;Kurokawa;Takashi
一个直接观测太阳系外行星的恒星日冕系统正在开发中，它结合了非平衡调零干涉仪（UNI）、自适应光学和焦平面掩模日冕仪1，2，3，4，5，6。采用λ/1000的高精度光学器件，通过λ/1000的高质量光学器件，可以达到很高的对比度。然而，在之前的实验中还没有获得足够高的对比度。认为最终日冕仪焦平面探测器处残留的散斑噪声是由λ/100级的“非共路误差”产生的，该“非共路误差”是日冕仪的波前误差，其不同于自适应光学的波前传感器（WFS）的波前误差，即使WFS指示λ/1000转换。非公共路径误差可以通过暗区方法来消除，暗区方法是通过在最终焦平面探测器处的波前感测来进行波前校正的方式，尽管由于反馈回路缓慢，它对于非常微弱的目标具有操作问题。在本文中，我们描述了我们的日冕系统变得实际上更高的对比度，通过升级的变形镜（DM）的控制方法与WFS辅助最终焦平面波前传感方法。在实验中我们实现了相对于星星的8×10- 7的对比度。
A stellar coronagraph system for direct observations of extra solar planets is under development by combining unbalanced nulling interferometer (UNI), adaptive optics, and a focal plane mask coronagraph1,2,3,4,5,6. It can reach a high contrast as using λ/10000 precision optics by λ/1000 quality ones. However, a sufficient high contrast is not obtained yet in the experiment before. It is thought that the remained speckle noise at the final coronagraph focal plane detector are produced by a “non-common path error” of λ/100 level, which is a wavefront error of the coronagraph different from that of a wavefront sensor (WFS) of adaptive optics, even when the WFS indicates λ/1000 conversion. The non-common path error can be removed by the dark zone method that is the way of wavefront correction by wavefront sensing at the final focal plane detector, although it has an issue of operation for very faint targets because of a slow feedback loop. In the present paper, we describe that our coronagraph system becomes practically higher contrast by upgrading the control method of deformable mirror (DM) with the WFS assisted by final focal plane wavefront sensing method. We accomplished contrast of 8×10-7relative to the star in experiment.