基于双螺旋结构的光纤马赫—曾德尔干涉仪传感器研究

发布时间：2018-05-24 06:57

  本文选题：光纤传感器 + 光纤马赫-曾德尔(MZ)干涉仪　； 参考：《吉林大学》2017年硕士论文

【摘要】：自从石英光纤出现以后,基于光纤的各项技术就顺势而生并且在短时间内得到了全面而迅速的发展。光纤的特殊性能使得它在传感和通信领域都扮演着举足轻重的作用。长久以来因为光纤类传感器拥有其他类传感器件不具备的许多优点而得到了科研人员的广泛关注。这些优点包括光纤传感器的尺寸较小、响应速度较快、能抗电磁干扰等等。目前常见的光纤传感器主要分为两类,即光纤干涉仪类传感器和光纤光栅类传感器。而光纤干涉仪类传感器相对于光纤光栅类传感器具有更高的灵敏度和更低的制备成本而被广泛应用到工程健康监测中。其中,作为光纤干涉仪类传感器中重要的一个分支,最近几年研究者们提出了多种基于新结构的光纤马赫-曾德尔(MZ)干涉仪传感器。论文通过利用光纤熔接机熔融,手动旋转光纤一端的方法制备了基于双螺旋结构(DHS)的MZ干涉仪光纤传感器。制备过程为通过先把一段去掉涂覆层并且用酒精棉擦拭干净的标准康宁单模光纤(SMF-28e)放置在光纤熔接机(Ericsson FSU-975)中,然后将光纤熔接机的程序重新设定为只放电不熔接程序,光纤的一端用熔接机自带的光纤夹具固定,另一端可以自由旋转,在放电的过程中手动旋转没有被固定的单模光纤的一端,最终形成一个螺旋结构,这个结构的形貌可以通过熔接机自带的CCD观察。再通过的同样的方式可以在同一根光纤上制备另一个螺旋结构,两个螺旋结构主要扮演着耦合器的作用。文中制备的这种全单模光纤结构的MZ干涉仪的两个螺旋结构的长度为7mm,且制备的器件没有改变光纤原有的直径,因此保证了光纤良好的机械强度。我们通过实验的方式测试了所制备的干涉仪的弯曲传感特性,得到干涉仪的透射光谱随着弯曲曲率的增加而蓝移并且弯曲灵敏度随弯曲曲率的增加呈现良好的线性关系。对于λ=1520 nm处的透射峰,在弯曲曲率从0.5m-1变化到3.059m-1时,实验得到的最大灵敏度为-35.27nm/m-1,同时我们做了3次弯曲重复实验,得出3次测试的结果基本一致,说明器件测试的可重复性,其次我们测试了当曲率从小变化到大和曲率从大变化到小的情况,得知两种测试情况对器件的弯曲灵敏度没有影响,所以该器件的弯曲灵敏度较高,且可以重复测量使用。另外,我们对器件温度的传感响应特性也进行了测试,在外界温度为30℃-90℃范围内,器件的温度灵敏度仅为63pm/℃。并对器件做了交叉灵敏度分析,得到外界温度的变化对器件的弯曲灵敏度的交叉灵敏度为0.0018m-1/℃,所以该传感器件的温度交叉灵敏度较低,可以较好的作为弯曲传感器使用。因为这种干涉仪的制备过程非常简单、成本低、弯曲灵敏度高、温度对弯曲测试影响小等特点,使得它在工程健康监测领域拥有广泛的市场前景。
[Abstract]:Since the emergence of quartz optical fiber, fiber-based technologies have come into being in a short period of time and have been fully and rapidly developed. The special performance of optical fiber makes it play an important role in the field of sensing and communication. For a long time, optical fiber sensors have many advantages that other sensor devices do not have. These advantages include the smaller size of the fiber sensor, the faster response speed, the ability to resist electromagnetic interference and so on. At present, there are two kinds of optical fiber sensors: fiber optic interferometer and fiber Bragg grating. Compared with fiber Bragg grating sensors, fiber optic interferometer sensors are widely used in engineering health monitoring because of their higher sensitivity and lower fabrication cost. In recent years, as an important branch of optical fiber interferometer sensors, researchers have proposed a variety of optical fiber Mach Zehnder MZ interferometer sensors based on a new structure. In this paper, the MZ interferometer optical fiber sensor based on double helix structure (DHS) is fabricated by using fiber fusion machine to melt and manually rotate one end of the fiber. The preparation process is to first remove the coating and wipe it with alcohol cotton in the fiber fusion machine Ericsson FSU-975) and then reset the procedure of the optical fiber fusion machine to discharge only non-weld procedure. One end of the fiber is fixed by the fiber-optic clamp brought by the welding machine, the other end is rotated freely, and one end of the unfixed single-mode fiber is manually rotated during the discharge process, and finally a spiral structure is formed. The morphology of the structure can be observed by CCD with the welding machine. In the same way, another helical structure can be fabricated on the same fiber. The two helical structures mainly act as couplers. The length of the two helical structures of the MZ interferometer is 7mm, and the fabricated device does not change the original diameter of the fiber, thus ensuring the good mechanical strength of the fiber. The bending sensing characteristics of the prepared interferometer are tested experimentally. It is found that the transmission spectrum of the interferometer moves blue with the increase of the curvature and the sensitivity of the interferometer shows a good linear relationship with the increase of the curvature of the interferometer. For the transmission peak at 1520 nm, the maximum sensitivity of the experiment is -35.27 nm / m ~ (-1) when the bending curvature changes from 0.5m-1 to 3.059m-1. At the same time, we have done three bending repeated experiments, and the results of three times are basically consistent, which shows the repeatability of the device test. Secondly, when curvature changes from small to large and curvature changes from large to small, we find that the two kinds of test conditions have no effect on the bending sensitivity of the device, so the bending sensitivity of the device is high and can be used repeatedly. In addition, the temperature sensing response of the device is also tested. The temperature sensitivity of the device is only 63pm/ 鈩，

本文编号：1928122