Prospects for fibre-optic evanescent-field gas sensors using absorption in the near-infrared
Prospects for fibre-optic evanescent-field gas sensors using absorption in the near-infrared
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DOI：
10.1016/s0925-4005(97)80169-4
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发表时间：
1997-01-01
影响因子：
8.4
通讯作者：
Culshaw, B
中科院分区：
文献类型：
--
作者：
Stewart, G;Jin, W;Culshaw, B
在本文中，我们研究了利用石英光纤传输窗口内的气体吸收线实现逝波型气体传感器的前景。我们的工作重点是甲烷，并使用D-光纤作为逝去场传感器。我们讨论了三个主要的障碍，即低灵敏度，高背景信号水平的干扰效应和系统退化的表面污染。我们解释了如何通过溶胶-凝胶涂层提高灵敏度，如何通过使用保偏光纤降低背景信号电平，并提出了一种通过连续监测D-光纤的双折射来补偿表面污染的方法，通过使用分布式反馈激光器而不是发光二极管可以改善性能，但成本要高得多。从长远来看，逝去场传感器可能在分布式测量系统中得到应用。
In this paper we investigate the prospects for realization of evanescent-wave gas sensors using gas absorption Lines within the transmission window of silica fibres. Our work focuses on methane and uses D-fibre as the evanescent-field sensor. We discuss the three major obstacles, namely, low sensitivity, high background signal levels from interference effects and system degradation through surface contamination. We explain how sensitivity may be improved through sol-gel coatings, how background signal levels may be reduced bg use of polarization-maintaining fibre and suggest a way of compensating for surface contamination by continuous monitoring of the birefringence of the D-fibre, Improved performance can be obtained through use of a distributed-feedback laser instead of a light-emitting diode, but at much greater cost. In the long term, the likely application for the evanescent-field sensor is in distributed measurement systems.