Improvement of functions in synthesis and scan of the optical co-herence function and its applications to distributed photonic sensing

作者发明了一种可以合成任意形状的光学相干函数的技术。此外，还发明了一种附加技术，通过对干涉仪中的参考光波进行相位调制来扫描函数。在本研究项目中，该原理被应用于构建新的分布式传感系统。首先，提出了基于co -相干函数合成的相位调制光学相干域折射技术（简称p-OCDR）。在以前的OCDR方法中，不仅要合成相干函数，还要通过半导体激光器的激光调频来扫描相干函数。相反，在p-OCDR中，扫描是通过相位调制完成的，这增加了合成形状的精度。考虑了p-OCDR的劣化因素，找到了相应的对策，实现了1.2mm的分辨率和-100 dB的灵敏度。为了诊断光纤到户系统中光纤分线器网络末端的设备，还提出了一种新型的高空间分辨率、远距离反射仪。以6cm的分辨率成功测量了远端约5Km处的反射率分布。接下来，将p-OCDR应用于测量保偏光纤中两个偏振本征模式之间的模式耦合分布，从而提供分布式压力传感系统。实验系统的分辨率达到9m，测量范围达到1Km。我们还研究了一种光纤干涉测量传感器的多路/解路输出方法。利用相干函数综合技术，成功地从多个传感器中选择了一个传感器的相位信息。此外，还提出了利用该技术的光学层析成像系统，其中不需要机械运动部件和任何计算。如上所述，这个研究项目已经积累了足够的研究成果。少

The author has invented a technique, in which optical coherence function can be synthesised in arbitrary shapes. Moreover, additional technique has also been invented to scan the function by using a phase modulation on the reference lightwave in the interferometer. In this research project, this principle is applied to construct new distributed sensing systems.At first, phase-modulationg Optical Coherence Domain Refrectomatry by Synthesis of CO-herence Function, p-OCDR for short, has been proposed. In the previous OCDR method, not only synthesising but also scanning the coherence function was carried out by the lasing frequency modulation of a semiconductor lase. On the contrary, in p-OCDR the scanning is done by the phase modulation, which results in increasing the accuracy of the synthesised shape. Deterioration factors in p-OCDR were considred to found the countermeasures, then 1.2mm resolution and -100 dB sensitivity have been realized. To diagnose divices at the end of optical sub … More scriber networks in the Fiber TO The Home system, new reflectometry with high spatial resolution and long range has also been proposed. Reflectivity distribution at about 5Km far end has successfully been measured with 6cm resolution. Next, p-OCDR has been applied to measure mode coupling distribution between two polalization eigen modes in a polalization maintaining fiber, which provide a distributed pressure sensing system. An experimental system has been constructed, which has shown the resolution of 9m and the measurable range of 1Km.We have also studied a method to mauti/demultiplex sensor outputs from fiber interfero-metric sensors. Phase information from one sensor has successfully been selected from others by using Synthesis of the Coherence Function Technique. Moreover, an optical tomography system has also been proposed utilising the thechnique, in which no mechanical moving part any calculation are needed.As described above, enough research results have been accululated on this research project. Less