arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2005.10737astro-ph.IM
收藏

大望远镜中单模光纤耦合特性的研究

Characterization of Single-Mode Fiber Coupling at the Large Binocular Telescope

Andrew J. Bechter, Jonathan Crass, Jonathan Tesch, Justin R. Crepp, Eric B. Bechter

摘要:

优化天空单模光纤(SMF)注入是开发精确多普勒光谱仪和新的天文光子学技术的重要组成部分。我们于2016年4月在大型双目望远镜(LBT)上安装并测试了SMF注入系统原型。光纤注入装置是作为一种名为iLocater的新仪器的风险降低过程的一部分而建造的,该仪器将使用自适应光学(AO)来馈送高分辨率近红外光谱仪。在本文中,我们报告Y波段SMF耦合测量明亮的M型恒星。我们比较理论预期的Strehl比和SMF耦合的实验结果,并评估基本的影响,限制注射效率。我们发现望远镜本身的光瞳几何形状限制了光纤耦合的最大效率rho_tel=0.78。进一步分析表明,AO校正、倾斜残差和静态(非共光路)像差的单独影响分别导致耦合系数rho_Strehl=0.33、rho_tip/tilt=0.84和rho_ncpa=0.8。综合起来,这些影响导致所有观测结果的平均Y波段SMF效率为0.18。最后,我们研究了光纤耦合对径向速度(RV)精度的影响,作为恒星视星等的函数。

英文摘要:

Optimizing on-sky single-mode fiber (SMF) injection is an essential part of developing precise Doppler spectrometers and new astrophotonics technologies. We installed and tested a prototype SMF injection system at the Large Binocular Telescope (LBT) in April 2016. The fiber injection unit was built as part of the de-risking process for a new instrument named iLocater that will use adaptive optics (AO) to feed a high resolution, near-infrared spectrograph. In this paper we report Y-band SMF coupling measurements for bright, M-type stars. We compare theoretical expectations for delivered Strehl ratio and SMF coupling to experimental results, and evaluate fundamental effects that limit injection efficiency. We find the pupil geometry of the telescope itself limits fiber coupling to a maximum efficiency of rho_tel=0.78. Further analysis shows the individual impact of AO correction, tip-tilt residuals, and static (non-common-path) aberrations contribute coupling coefficients of rho_Strehl=0.33, rho_tip/tilt=0.84, and rho_ncpa=0.8 respectively. Combined, these effects resulted in an average Y-band SMF efficiency of 0.18 for all observations. Finally, we investigate the impact of fiber coupling on radial velocity (RV) precision as a function of stellar apparent magnitude.

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。

↑