Fiber-loop ring-down spectroscopy
Fiber-loop ring-down spectroscopy
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DOI：
10.1063/1.1527893
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发表时间：
2002-12-15
影响因子：
4.4
通讯作者：
Loock, HP
中科院分区：
文献类型：
--
作者：
Brown, RS;Kozin, I;Loock, HP
脉冲、可见光和近红外激光耦合到光纤中，光纤使用光纤接头连接器缠绕成环。使用光电倍增管检测器检测通过光纤环行进的光脉冲。研究发现，一旦光耦合到光纤中，它就会经历非常小的损耗，并且光脉冲在其强度低于检测阈值之前会进行大量的往返。每次通过损耗和衰荡时间的测量允许表征光纤和接头连接器中光脉冲的不同损耗机制。这种方法类似于“腔衰荡吸收光谱”，非常适合于表征独立于光源功率波动的光纤传输中的低损耗过程。它表明，通过测量衰荡时间，可以准确地确定绝对传输的光纤和光纤连接器。此外，它表明，该技术是有用的非常小的样品体积的吸收光谱技术。将有机染料溶液置于纤维端部之间，而不是通常的折射率匹配流体，并记录7 × 10（-15）mol染料1，1（′）-二乙基-4，4（′）-二碳菁碘化物在7 × 10（-12）L二甲亚砜中的吸收光谱。(C)2002年美国物理学会。
Pulsed, visible and near-infrared laser light is coupled into an optical fiber, which is wound into a loop using a fiber splice connector. The light pulses traveling through the fiber-loop are detected using a photomultiplier detector. It is found that once the light is coupled into the fiber it experiences very little loss and the light pulses do a large number of round trips before their intensity is below the detection threshold. Measurements of the loss-per-pass and of the ring-down time allow for characterization of the different loss mechanisms of the light pulses in the fiber and splice connector. This method resembles "cavity ring-down absorption spectroscopy" and is well suited to characterize low-loss processes in fiber optic transmission independent from power fluctuations of the light source. It is demonstrated that by measuring the ring-down times one can accurately determine the absolute transmission of an optical fiber and of the fiber connector. In addition it is demonstrated that the technique is useful as an absorption spectroscopic technique of very small sample volumes. A solution of an organic dye was placed between the fiber ends instead of the usual index matching fluid, and an absorption spectrum of 7x10(-15) mol of the dye 1,1(')-diethyl-4,4(')-dicarbocyanine iodide in 7x10(-12) L of dimethylsulfoxide was recorded. (C) 2002 American Institute of Physics.