A modified method for determining the focal ratio degradation and length properties of optical fibres in astronomy

	A modified method for determining the focal ratio degradation and length properties of optical fibres in astronomy
	Yan, Yunxiang 1,2; Wang, Gang1 ; Sun, Weimin 3; Luo, A-Li1 ; Ma, Zhenyu 3; Li, Jian 1; Wang, Shuqing1
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2017-04-01
卷号	466 期号:2 页码:1669-1687
关键词	instrumentation: miscellaneous instrumentation: spectrographs methods: data analysis techniques: miscellaneous techniques: spectroscopic
英文摘要	Focal ratio degradation (FRD) is a major contributor to throughput and light loss in a fibre spectroscopic telescope system. We combine the guided mode theory in geometric optics and a well-known model, the power distribution model (PDM), to predict and explain the FRD dependence properties. We present a robust method by modifying the energy distribution method with f-intercept to control the input condition. This method provides away to determine the proper position of the fibre end on the focal plane to improve energy utilization and FRD performance, which lifts the relative throughput up to 95 per cent with variation of output focal ratio less than 2 per cent. This method can also help to optimize the arrangement of the position of focal-plane plate to enhance the coupling efficiency in a telescope. To investigate length properties, we modified the PDM by introducing a new parameter, the focal distance f, into the original model to make it available for a multiposition measurement system. The results show that the modified model is robust and feasible for measuring the key parameter d(0) to simulate the transmission characteristics. The output focal ratio in the experiment does not follow the prediction trend but shows an interesting phenomenon: the output focal ratio increases first to the peak, then decreases and remains stable finally with increasing fibre length longer than 15 m. This provides a reference for choosing the appropriate length of fibre to improve the FRD performance for the design of the fibre system in a telescope.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	INSTRUMENTATION
收录类别	SCI
语种	英语
WOS记录号	WOS:000398284600027
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/8255]
专题	国家天文台_应用天文研究部
作者单位	1.Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, Beijing 100012, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Harbin Engn Univ, Key Lab Infiber Integrated Opt, Minist Educ China, Harbin 150001, Peoples R China
推荐引用方式 GB/T 7714	Yan, Yunxiang,Wang, Gang,Sun, Weimin,et al. A modified method for determining the focal ratio degradation and length properties of optical fibres in astronomy[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2017,466(2):1669-1687.
APA	Yan, Yunxiang.,Wang, Gang.,Sun, Weimin.,Luo, A-Li.,Ma, Zhenyu.,...&Wang, Shuqing.(2017).A modified method for determining the focal ratio degradation and length properties of optical fibres in astronomy.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,466(2),1669-1687.
MLA	Yan, Yunxiang,et al."A modified method for determining the focal ratio degradation and length properties of optical fibres in astronomy".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 466.2(2017):1669-1687.