【作者】 程华奇；

【导师】 荆振国；

【作者基本信息】 大连理工大学 ， 光学工程， 2012， 硕士

【摘要】 相比传统的传感器,光纤传感器具有许多独一无二的优点,在许多领域有着广泛研究与应用。光纤干涉型传感器具有高灵敏度等优点而成为光纤传感器最实用的一种。基于迈克尔逊干涉原理的光纤传感器具有制作简单、测量便利等优点而成为光纤干涉型传感器研究中很常见的一种。光纤折射率传感器具有较大的应用价值,主要在生物、化学、医药等领域应用较为广泛。一种基于迈克尔逊干涉原理的新型光纤传感器在本文中得到了实现,叫单模偏芯光纤折射率传感器,通过偏芯将光从纤芯耦合到包层中。借助光束传播法(BPM),得出了外界环境折射率与包层模的有效折射率关系以及基模与部分包层模间的耦合关系。理论结果表明：随着外界环境折射率值的增大,基模的有效折射率保持不变,而包层模的有效折射率值则逐渐变大,当外界环境折射率的值接近包层折射率时,包层模的有效折射率值变化越明显；随着偏心距离的增大,基模的耦和效率迅速变小,而包层模的耦合效率逐渐变大,最后趋向一个定值。特征波长随着外界环境折射率的增加而向减小的方向移动。利用实验中制作的单模偏芯传感器相继对溶液折射率测量、结构的温度敏感性和折射率测量的温度补偿效应进行了实验研究。实验结果与理论分析基本一致,液体折射率与特征波长有着单调的递减关系,而温度与特征波长有着很好的线性关系。实验中能够通过温度实验来实现一定程度的温度补偿,以减小温度对折射率测量的影响。更多还原

【Abstract】 With many unique advantages compared to traditional sensors, optical fiber sensors have been studied and applied to many different areas. Interferometric sensors are one of the most useful sensor types due to their high sensitivities and relatively relaxed requirement on the stability of the optical source’s power level. Optical sensors based on the principle of Michelson interferometer are one of the most popular sensor types due to their simple-structure and measurement facilities. Fiber refractive index sensors have so many available applications extremely in the field of biology, chemistry, medicine and so on.Based on the principle of Michelson interferometer, a new kind of optical sensor is developed. We call it single-mode core-offset optical sensor which couple light from core to cladding to replace LPG. We get the relationship between surrounding RI and cladding’s effective RI with BPM. The coupling coefficients between core and cladding modes are calculated by it too. The results show that the effective RI of the cladding mode increases while the surrounding RI increasing and the effective RI of the core mode stays almost at constant; each mode’s coupling efficiency changes gradually and finally reaches a fixed value with the increasing of core-offset distance. The characteristic wavelength will shift to short wavelength direction when the surrounding RI increases.The experiment results include three parts:the result of sugar solution’s RI, the result of aqueous solution after temperature compensation and the result of high temperature. The result fit well with theoretical analysis, Experimental results show that there will be an increasing relationship between characteristic wavelength and temperature. There will be a better decrease gradually relationship between characteristic wavelength and refractive index after temperature compensation.更多还原