RISTRETTO：用于在可见光波段探测比邻星b的VLT极自适应光学设计
RISTRETTO: a VLT XAO design to reach Proxima Cen b in the visible
AI总结：
本研究提出甚大望远镜访客仪器RISTRETTO的极自适应光学架构，采用双传感器单变形镜等设计，通过端到端仿真验证其可在可见光低风效应下实现高对比度，为近邻系外行星大气表征提供支撑。
摘要：
RISTRETTO是将甚大望远镜（VLT）的SPHERE与ESPRESSO仪器耦合这一最初构想的演进版本，旨在实现高色散日冕观测。RISTRETTO是一台访客仪器，通过高对比度高分辨率光谱技术，可对近邻系外行星的反射光大气进行表征，其观测目标为比邻星b（Prox Cen b）及其他与宿主恒星角间距约35毫角秒的行星，该间距在波长750纳米处对应2λ/D。该仪器由极自适应光学系统、日冕式积分视场单元以及一台衍射极限光谱仪（分辨率R=140000，波长范围620-840纳米）组成。\n我们提出了满足性能指标的RISTRETTO极自适应光学（XAO）架构，在存在大气及低风效应的可见光波段，该架构在距恒星2λ/D处的对比度可低至5×10^-5。这一性能得益于一种新型的双传感器单变形镜架构，对已知的无调制金字塔波前传感器（pyWFS）和泽尼克波前传感器（zWFS）概念的若干改进，以及对当前最先进的高速低噪声相机与快速变形镜性能的最大化利用。我们还展示了端到端仿真的结果，证明了无调制金字塔波前传感器与泽尼克波前传感器协同工作时，在低风效应下可实现稳定的闭环运行。
英文摘要：
RISTRETTO is the evolution of the original idea of coupling the VLT instruments SPHERE and ESPRESSO \cite{lovis_2016a}, aiming at High Dispersion Coronagraphy. RISTRETTO is a visitor instrument that should enable the characterization of the atmospheres of nearby exoplanets in reflected light, by using the technique of high-contrast, high-resolution spectroscopy. Its goal is to observe Prox Cen b and other planets placed at about 35mas from their star, i.e. $2λ/D$ at $λ$=750nm. The instrument is composed of an extreme adaptive optics, a coronagraphic Integral Field Unit, and a diffraction-limited spectrograph (R=140.000, $λ=$620-840 nm). We present the RISTRETTO XAO architecture that reach the specification, providing contrasts down to $5\times10^{-5}$ at 2$λ/D$ from the star in the visible, in the presence of atmosphere and low wind effect. This performance is allowed by a new two-sensors-one-dm architecture, some variations to the already known concepts of unmodulated pyWFS and zWFS, and exploiting to the maximum of their capabilities the state-of-the-art high speed, low noise cameras \& fast DM. We present the result of end-to-end simulations, that demonstrate stable closed loop operation of an unmodulated pyramid and a zernike WFS (together), and in presence of low wind effect.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
