发表机构
University of Bern; Université Paris Cité, Observatoire de Paris, Université PSL, Sorbonne Université, CNRS（伯尔尼大学; 巴黎西岱大学，巴黎天文台，巴黎文理研究大学，索邦大学，法国国家科学研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文研究采用像素化离散焦平面掩膜的主动日冕仪性能，明确其主要误差源与限制参数，指出该类器件适用于地基高对比度成像，相关结论也适用于其他离散像素化焦平面相位掩膜。
AI 中文摘要
高对比度系外行星成像仪器的最新进展催生了主动日冕仪的概念，例如硅基液晶空间光调制器（可作为可编程相位掩膜）或数字微镜器件（可作为可配置光瞳 apodizer）。主动日冕仪能够实时调整以适应不断变化的观测条件和科学目标，例如在盲天区巡天与已知天体后续观测间切换，或优化对包含双星、三星的多恒星系统的观测。与此同时，这些主动器件也带来了挑战：有限的空间采样、受限的相位分辨率以及其调制的标量特性均会降低日冕仪性能。本文研究采用像素化离散焦平面掩膜（FPM）的日冕仪性能随各关键参数的变化，这些参数包括空间采样、相位分辨率、时间抖动和校准误差。分析涵盖多种 FPM 设计：涡旋型、四象限相位掩膜、Roddier 与 Roddier 型、双区相位掩膜以及方位角余弦相位掩膜。研究同时考虑单色成像和带宽为 20% 的宽带成像条件，以及望远镜光瞳中是否存在次镜导致的中心遮挡（对应 Lyot 光阑尺寸的变化）。结果明确了标量像素化 FPM 日冕仪的主要误差源和限制参数：理想条件下，性能主要受空间采样和标量相位调制的色像差限制，因此这类器件主要适用于地基高对比度成像，而非未来空间望远镜所需的更深对比度区域；尽管研究主要基于空间光调制器（SLM）的实现，但结论也适用于其他离散像素化焦平面相位掩膜。
英文摘要
Recent advances in high-contrast exoplanet imaging instrumentation have introduced the concept of adaptive coronagraphy. For example, liquid-crystal-on-silicon spatial light modulators can be used as programmable phase masks or digital micro-mirror devices as configurable pupil apodizers. Adaptive coronagraphy offers the ability to adjust in real time to changing observing conditions and science goals, such as switching between blind surveys and follow-ups of known objects, or optimizing observations of multiple star systems including binaries and triples. At the same time, these active devices present challenges: finite spatial sampling, limited phase resolution, and the scalar nature of their modulation can all reduce coronagraphic performance. We look at the performance of a coronagraph utilizing pixelated discrete focal plane masks in function of various key parameters, notably spatial sampling, phase resolution, temporal jitter, and calibration errors. The analysis includes several FPM designs: vortex, four-quadrant phase mask, Roddier and Roddier, dual-zone phase mask, and azimuthal cosine phase mask. Both monochromatic and 20% broadband imaging conditions are considered, along with the absence or presence of a central obstruction from a secondary mirror in the telescope pupil, associated with variations in Lyot stop sizing. Our results identify the main error sources and limiting parameters of scalar, pixelated FPM coronagraphs. Under ideal conditions, performance is mainly limited by spatial sampling and chromaticity of scalar phase modulation. These devices are therefore primarily relevant to ground-based high-contrast imaging rather than the deeper contrast regimes required by future space observatories. Although motivated mainly by SLM implementations, the conclusions should also apply to other discrete pixelated focal-plane phase masks.
CommentsAccepted in Journal of Astronomical Telescopes, Instruments, and Systems (JATIS), 48 pages, 20 figures
