塑料光纤的结构修饰及其折射率传感特性研究

发布时间：2018-04-25 04:02

本文选题：塑料光纤 + 多模光纤　；参考：《吉林大学》2017年博士论文

【摘要】：折射率是材料和物质的重要光学参数之一,对它的测量可以直接或间接反映被测物质和材料的浓度、温度以及应力等性质和状态。因此,折射率传感技术可以在生物、化学以及医疗等领域得到应用。利用光纤传感技术测量折射率,具有响应速度快、抗电磁干扰、可进行远程操作等优点,被人们广泛研究,并取得了较好的进展。目前人们提出了许多基于光纤传感技术的折射率传感器,其中大多数都属于石英光纤基的折射率传感器,而随着人们对低价格、一次性使用的生化传感器的追求,塑料光纤折射率传感器引起了人们的关注,因为塑料光纤具有价格低廉、易于加工与连接、可见光操作等特点,是实现廉价折射率传感解决方案的理想光纤。本论文以实现低成本和高灵敏的折射率传感为目的,对塑料光纤的结构进行拉锥、侧抛,以及机械压模等修饰改造。提出并制备了三种不同结构的塑料光纤折射率传感器,即拉锥、侧抛以及长周期光栅(LPG)型塑料光纤折射率传感器。研究了它们的折射率传感特性,通过优化结构参数,提高了器件的传感特性。得到的主要研究结果如下:首先,采用热熔拉伸法制备了不同锥腰直径的锥形塑料光纤,并利用热定型法将其制成了U形拉锥塑料光纤折射率传感探头。将锥形与宏弯曲结构相结合,提高了折射率的传感特性。主要研究了光纤的锥腰直径,宏弯曲曲率半径以及是否带有包层等因素对其传感特性的影响。研究得到,带包层U形拉锥塑料光纤的折射率传感范围为1.333-1.410,当宏弯曲曲率半径和锥腰直径分别为2.0mm和250μm时,其灵敏度可达937%/RIU,分辨率为7.11×10-4RIU。通过去掉包层,其折射率的传感范围扩大到1.333-1.450,但灵敏度有所下降,为800%/RIU,分辨率为5.55×10-4RIU。另外,我们还分析与研究了该种光纤探头在10-60℃下的温度依赖特性,并给出了温度补偿的方法。其次,采用抛磨的方法制备了侧抛塑料光纤,研究了直条形和U形两种侧抛塑料光纤的折射率传感特性。研究发现,直条形侧抛塑料光纤对折射率传感的灵敏度不高,而将其弯曲制成U形结构探头之后,传感特性有明显的提升。因此,我们重点研究了U形侧抛塑料光纤的折射率传感特性,不仅分析了光纤结构参数对折射率传感灵敏度的影响,还分析了分辨率、线性度、重复性以及温度依赖特性等指标参数。结果显示,当塑料光纤的抛磨深度为400μm,抛磨长度为10 mm,宏弯曲曲率半径为2.0 mm时,其折射率传感特性最优,在1.333-1.450测量范围内的灵敏度可达864%/RIU,分辨率为3.3×10-4RIU。此外,还分析了塑料光纤表面抛磨质量对折射率传感特性的影响。最后,探索了一种简单的机械压模方法,用其制备了塑料光纤多沟槽结构的LPG,并研究了它的折射率传感特性。分别研究了带有LPG的直条形和U形塑料光纤的折射率传感特性。研究发现,直条形塑料光纤LPG对折射率的变化不太敏感,但却可以得到一个较大的折射率测量范围,在1.333-1.410和1.410-1.450的折射率范围内,其灵敏度分别为143%/RIU和287%/RIU。而将其宏弯曲以后,在1.333-1.410的折射率测量范围内,其折射率传感特性得到了明显提升。通过改变塑料光纤的结构参数,优化了其折射率的传感特性。当U形塑料光纤LPG探头的宏弯曲曲率半径为3mm,LPG沟槽深度为200μm、长度为10 mm、周期为1 mm时,传感器的灵敏度与分辨率分别为1130%/RIU和8.44×10-4 RIU。最后,我们还给出了该传感探头的线性度、重复性及温度稳定性等特性指标。
[Abstract]:Refractive index is one of the important optical parameters of material and material. The measurement of the refractive index can directly or indirectly reflect the properties and states of the measured material and material, such as the temperature and stress. Therefore, the refractive index sensing technology can be used in the fields of biology, chemistry and medical treatment. Due to the advantages of fast speed, anti electromagnetic interference and remote operation, it has been widely studied and made good progress. At present, many refractive index sensors based on optical fiber sensing technology have been proposed, most of which belong to the refractive index sensor of quartz fiber base, and with people's low price, a one-time use of biochemical transmission. The refractive index sensor of plastic optical fiber has attracted people's attention because of its low price, easy processing and connection, visible light operation and so on. It is an ideal optical fiber for the realization of low cost refractive index sensing solution. This paper aims at realizing low cost and high sensitive refractive index sensing. The structure is modified with taper, side throwing, and mechanical die pressure modification. Three kinds of refractive index sensors for plastic optical fiber are proposed and fabricated, which are taper, side throwing and long period grating (LPG) plastic fiber refractive index sensor. The characteristics of their refractive index sensing are studied. By optimizing the structure parameters, the sensor sensor is improved. The main results obtained are as follows: first, the tapered plastic optical fiber with different cone and waist diameter is prepared by hot melt drawing, and the refractive index sensor of U shaped taper plastic fiber is made by heat setting method. The sensing characteristic of the refractive index is improved by combining the conical and macro bending structure, and the conical waist of the fiber is mainly studied. The influence of the diameter, the radius of the curvature of the macro curvature and the inclusion of the cladding on its sensing characteristics is studied. It is obtained that the refractive index sensing range of the U shaped taper plastic fiber with a cladding is 1.333-1.410. When the radius of curvature of the macro and the diameter of the conical waist is 2.0mm and 250 m respectively, the sensitivity can reach 937%/RIU and the resolution is 7.11 x 10-4RIU.. The sensing range of the refractive index is expanded to 1.333-1.450, but the sensitivity is reduced to 800%/RIU and the resolution is 5.55 x 10-4RIU.. We also analyze and study the temperature dependence of this kind of optical fiber probe at 10-60 C, and give the method of temperature compensation. Secondly, the side throwing plastic fiber is prepared by the method of polishing. The refractive index sensing characteristics of two kinds of side throwing plastic fibers with straight bar and U shape are studied. It is found that the sensitivity of the straight stripe flside plastic fiber to the refractive index sensing is not high, and the sensing characteristic of the U shaped structure probe is obviously improved after it is bent into the probe. Therefore, we focus on the refractive index sensing of the U shaped side throwing plastic fiber. Not only the influence of optical fiber structure parameters on the sensitivity of refractive index sensing is analyzed, but also the parameters such as resolution, linearity, repeatability and temperature dependence are also analyzed. The results show that when the polishing depth of the plastic fiber is 400 m, the polishing length is 10 mm and the radius of the macro curvature is 2 mm, the refractive index sensing characteristic is optimal, at 1.. The sensitivity of the 333-1.450 measurement range is up to 864%/RIU, with a resolution of 3.3 x 10-4RIU.. The influence of the quality of the surface polishing of the plastic optical fiber on the refractive index sensing characteristics is also analyzed. Finally, a simple mechanical die pressing method is explored. The LPG of the multi groove structure of the plastic optical fiber is prepared and its refractive index sensing characteristics are studied. The refractive index sensing characteristics of the straight strip and U shaped plastic optical fiber with LPG are studied respectively. It is found that the straight bar plastic fiber LPG is not very sensitive to the change of the refractive index, but it can get a larger measurement range of refractive index. The sensitivity is 143%/RIU and 287%/RIU. in the refractive index of 1.333-1.410 and 1.410-1.450, respectively. After bending the macro, the refractive index sensing characteristics of 1.333-1.410 are obviously improved in the range of refractive index measurement. By changing the structural parameters of the plastic optical fiber, the sensing characteristics of the refractive index are optimized. When the curvature radius of the U shaped plastic optical fiber LPG probe is 3mm, the LPG groove depth is 200 u m, the length is 10 mm, and the cycle is 1. At mm, the sensitivity and resolution of the sensor are 1130%/RIU and 8.44 x 10-4 RIU., respectively. We also give the linearity, repeatability and temperature stability of the sensor.

【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN253

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