Sirbu Dan, Kasdin N Jeremy, Vanderbei Robert J
Opt Express. 2013 Dec 30;21(26):32234-53. doi: 10.1364/OE.21.032234.
One of the most promising concepts of starlight suppression for direct imaging of exoplanets is flying a specially-shaped external occulter in formation with a space telescope. Here we present contrast performance verification of an occulter design scaled to laboratory-size using Fresnel numbers corresponding to the space design. Experimental design innovations include usage of an expanding beam to minimize phase aberrations, and an outer ring to minimize hard-edge diffraction effects. The apodizing performance of the optimized occulter edge is compared with a baseline case of a circular occulter and shown to result in contrast improvements. Experimental results in red monochromatic light show that the achieved laboratory contrast exceeds ten orders of magnitude, but with differences from the theoretical diffraction analysis limited by specular reflection from the mask edges.
对于系外行星直接成像而言，最具前景的星光抑制概念之一是让一个特殊形状的外部遮光板与太空望远镜编队飞行。在此，我们展示了一种遮光板设计的对比度性能验证，该设计按与太空设计对应的菲涅尔数缩放到实验室尺寸。实验设计创新包括使用扩展光束以最小化相位像差，以及使用外环以最小化硬边衍射效应。将优化后的遮光板边缘的变迹性能与圆形遮光板的基线情况进行比较，结果表明对比度得到了改善。红色单色光的实验结果表明，实现的实验室对比度超过了十个数量级，但与理论衍射分析的差异受掩模边缘镜面反射的限制。
