Characterization of hexabundles: initial results
Characterization of hexabundles: initial results
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六束的表征：初步结果
DOI：
10.1111/j.1365-2966.2011.18841.x
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发表时间：
2011
影响因子：
4.8
通讯作者：
S. Leon
中科院分区：
文献类型：
--
作者：
J. Bryant;John O'Byrne;J. Bland;S. Leon
悉尼大学正在开发的新的多核成像光纤束--六元光纤束--将为数百个天体源在一个宽角范围内提供同时的积分场光谱学。这些都是现有星系调查中使用单一纤维的自然过程。六丰度谱将使我们能够解决天文学中的基本问题，而不会因为固定的入射光圈而产生偏差。我们已经开始考虑在尽可能宽的视野内利用数百个六价元素的乐器概念。为此，我们比较了61核全融合六叉和五个各有七核的轻融合束的性能。束中的所有光纤都有100-μm芯。在全熔合束中，芯从圆形变形，以获得更高的填充百分比。轻熔焊束具有圆形芯和五种不同的包层厚度，这些厚度会影响填充分数。我们比较了所有六种光束的光学性能，发现较小的间隙空穴(较高的填充分数)的优势被模式耦合和串扰的增加以及光纤芯变形导致的光学性能差所盖过。均匀的高通量和低串扰对于以足够的分辨率成像微弱的天文目标以解开动力学结构是必不可少的。已经在开发中的设备将拥有100到200个轻度融合的核心，尽管更大的格式是可行的。六氟化铅的轻质包装足够灵活，可以让现有的机器人定位器使用它们。
New multicore imaging fibre bundles – hexabundles – being developed at the University of Sydney will provide simultaneous integral field spectroscopy for hundreds of celestial sources across a wide angular field. These are a natural progression from the use of single fibres in existing galaxy surveys. Hexabundles will allow us to address fundamental questions in astronomy without the biases introduced by a fixed entrance aperture. We have begun to consider instrument concepts that exploit hundreds of hexabundles over the widest possible field of view. To this end, we have compared the performance of a 61-core fully fused hexabundle and five lightly fused bundles with seven cores each. All fibres in the bundles have 100-μm cores. In the fully fused bundle, the cores are distorted from a circular shape in order to achieve a higher fill fraction. The lightly fused bundles have circular cores and five different cladding thicknesses which affect the fill fraction. We compare the optical performance of all the six bundles and find that the advantage of smaller interstitial holes (higher fill fraction) is outweighed by the increase in modal coupling, cross-talk and the poor optical performance caused by the deformation of the fibre cores. Uniformly high throughput and low cross-talk are essential for imaging faint astronomical targets with sufficient resolution to disentangle the dynamical structure. Devices already under development will have between 100 and 200 lightly fused cores, although larger formats are feasible. The light-weight packaging of hexabundles is sufficiently flexible to allow existing robotic positioners to make use of them.