STS光纤结构折射率传感特性研究

发布时间：2018-03-12 09:14

本文选题：光纤传感器　切入点：液体折射率检测　出处：《山东科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：光纤传感技术,一般是通过各种增敏封装结构或光纤本身参数随着外界物理量变化,而引起光纤中的光波参数变化,进而感知和传输外界被测信号的一种传感技术。光纤传感器一经产生就以其独特的特性而得到广泛应用,尤其电绝缘性,化学稳定性,耐腐蚀和抗干扰等。尤其在液体折射率检测方面,光纤传感器的灵敏度高,柔性韧性好,传感器体积小,可以制成不同形状,耐腐蚀和大量程的独特优势更加显著。随着各行各业对于检测技术的要求越来越高,对于液体折射率传感器也提出了更高的要求。本论文针对全光纤结构光纤液体折射率传感器进行研究,该类传感器较现有的光纤光栅类折射率传感器,具有更高的灵敏度,结构简单,成本低和易于实现等特点。然而,大量已有研究结果显示,该类传感器在低浓度液体折射率检测方面还有待发展,因此,本论文以单模-小芯径-单模(STS)光纤结构构成的全光纤Mach-Zehnder干涉仪式的光纤折射率传感器为目标,对其折射率传感特性进行了研究,尤其对于该类传感器在小折射率浓度下的灵敏度提高方面进行了研究,并提出了增加灵敏度传感器结构方案,论文主要的研究工作如下:1、STS结构传感器的系统的理论和实验研究。在单模与小芯径光纤的传光原理基础上,研究了传感器输出光谱与光纤参数关系。实验研究了该传感器输出谱干涉波长与液体折射率关系,实验获得了不同波长(1541nm和1555nm)的条件下折射率与波长的关系曲线及传感器灵敏度与波长关系。2、实验研究了弯曲增敏STS光纤结构与折射率关系。获得了不同光纤弯曲直径(9.6cm, 8.3cm, 7.5cm)下传感器干涉波长漂移与折射率变化关系曲线。分别测量了 1%-10%Nacl和1.335-1.4384溶液折射率与传感器输出干涉波长关系,可见,通过对敏感部分光纤弯曲,可以有效的提高传感器折射率灵敏度,对于低浓度液体折射率检测尤其有效。3、去部分包层STS光纤液体折射率传感特性研究。实验中,通过去除敏感部分光纤部分包层方法也可以提高传感器灵敏度,并对实验方法和过程进行了详细论述。实验结果表明,腐蚀后的STS全光纤折射率传感器对小折射率具有很好的灵敏度。对于0-1%和1%-10%Nacl溶液折射率不同波长(1539.43nm和1545.5nm)具有不同的灵敏度,波长与折射率变化有较高的线性拟合度。
[Abstract]:The optical fiber sensing technology usually changes the optical wave parameters in the optical fiber by various sensitized packaging structures or the parameters of the fiber itself with the change of the external physical quantity. A sensing technique for sensing and transmitting external measured signals. Optical fiber sensors are widely used because of their unique characteristics, especially electrical insulation and chemical stability. Especially in liquid refractive index measurement, optical fiber sensors have high sensitivity, good flexibility and toughness, small size, and can be made into different shapes. The unique advantages of corrosion resistance and mass range are even more significant. In this thesis, the fiber optic fiber refractive index sensor with all-fiber structure is studied, which has higher sensitivity than the existing fiber Bragg grating refractive index sensor. The structure is simple, the cost is low and the realization is easy. However, a large number of research results show that this kind of sensors still need to be developed in low concentration liquid refractive index detection, so, In this paper, the refractive index sensor of all-fiber Mach-Zehnder interferometric ceremony is studied, which is composed of single-mode, small-core diameter and single-mode STS fiber structure. In particular, the sensitivity of this kind of sensors under the small refractive index concentration is studied, and the scheme of increasing sensitivity sensor structure is proposed. The main research work of this thesis is as follows: theoretical and experimental research on the system of the 1: 1 STS structure sensor. On the basis of the light transmission principle of single mode and small core diameter fiber, The relationship between the output spectrum of the sensor and the parameters of the optical fiber is studied, and the relationship between the interference wavelength of the output spectrum of the sensor and the refractive index of the liquid is experimentally studied. The relationship curves between refractive index and wavelength and sensitivity of sensor with wavelength of 1541nm and 1555nm were obtained experimentally. The relationship between structure and refractive index of bending sensitized STS fiber was studied experimentally, and the relationship between refractive index of different fiber bending was obtained. The relationship between the interference wavelength shift and the refractive index change of the sensor at the diameter of 9.6cm, 8.3cm, 7.5cm) has been measured, respectively. The relationship between the refractive index of 1-10Nacl and 1.335-1.4384 solution and the output interference wavelength of the sensor has been measured. It can be seen that the sensitivity of sensor refractive index can be improved effectively by bending the sensitive part of fiber, especially for low concentration liquid refractive index detection. The liquid refractive index sensing characteristics of partially clad STS fiber are studied. The sensitivity of the sensor can also be improved by removing the sensitive part of the fiber partial cladding, and the experimental method and process are discussed in detail. The experimental results show that, The corroded STS all-fiber refractive index sensor has good sensitivity for small refractive index, and has different sensitivity for 0-1% and 1% -10 NaCl solution refractive index at different wavelengths 1539.43 nm and 1545.5 nm.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN253;TP212

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