Correcting polarization crosstalk in the ESPaDOnS spectro-polarimeter
Correcting polarization crosstalk in the ESPaDOnS spectro-polarimeter
复制标题
校正 ESPaDOnS 分光偏振计中的偏振串扰
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
D. Sabin
中科院分区：
文献类型：
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作者：
G. Barrick;T. Benedict;D. Sabin
ESPaDOnS 是加拿大-法国-夏威夷望远镜 (CFHT) 使用的高分辨率、交叉色散、光纤馈送、阶梯光栅摄谱仪。来自望远镜的光在注入光谱仪的光纤之前先经过偏振计级，因此该仪器能够确定波长为 370 - 1000 nm 的恒星光谱的偏振。偏振测量精度的一个限制是在偏振分析之前所有光学器件不可避免地会产生偏振串扰。这种串扰的主要来源是光学玻璃中的应力双折射；要么是退火过程中的残留物，要么是由光学器件的安装引起的。本文讨论了 ESPaDOnS 中的串扰从 5% 或以上降低到 1% 以下的过程。
ESPaDOnS is a high-resolution, cross-dispersed, fiber fed, echelle spectrograph in use at the Canada-France-Hawaii Telescope (CFHT). The light from the telescope passes through a polarimeter stage before being injected into the fibers that feed the spectrograph, so the instrument is capable of determining the polarization of the stellar spectra from 370 - 1000 nm in wavelength. One limit to the accuracy of the polarimetry is the inevitable polarization crosstalk added by all optics prior to polarization analysis. The main source of this crosstalk is stress birefringence in the glass of the optics; either residual from the annealing process or induced by the mounting of the optics. The process by which the crosstalk in ESPaDOnS has been reduced from 5% or more to less than 1% is discussed in this paper.