【作者】 李捷；

【导师】 何伟；

【作者基本信息】 武汉理工大学 ， 通信与信息系统， 2005， 硕士

【摘要】 在光纤光栅传感器中所使用的光纤光栅主要是短周期光纤光栅和长周期光纤光栅,我们所说的短周期光纤光栅就是普通的等周期光纤布喇格光栅,短周期光纤光栅由于其良好的传感特性和比较成熟的解调手段,已经在传感领域得到广泛地应用。长周期光纤光栅相对于短周期光纤光栅发展得比较晚,还没有得到广泛地应用,但长周期光纤光栅有其独特的传感特性,比如:有比较敏感的应变和温度特性;有比较敏感的双折射特性;对周围介质折射率敏感等,由于这些特性,近年来长周期光纤光栅传感器的研究也越来越受到广泛地关注。 将长周期光纤光栅和短周期光纤光栅重叠写入光纤的同一位置,可以得到既具有长周期光纤光栅特性又具有短周期光纤光栅特性的光纤光栅,我们将这种光纤光栅称之为长短双周期光纤光栅。这种长短双周期光纤光栅中的长周期光纤光栅信号和短周期光纤光栅的信号互不干扰,在光纤反射端,只能观察到短周期光纤光栅的反射谱;在光纤透射端,长周期光纤光栅和短周期光纤光栅的信号都可以观察到,但是短周期光纤光栅的透射谱不影响长周期光纤光栅透射谱。本文对这种长短双周期光纤光栅的制作和传感特性进行了研究,在此基础上,探讨了三种基于长短双周期光纤光栅的应用: 1、温度和应变的同时测量; 2、多轴应变的同时测量: 3、编码波分复用技术。 并对以上三方面的应用进行了理论和实验研究。 本文做了如下主要工作 (1)对长短双周期光纤光栅的制作进行了研究; (2)从理论上对长短双周期光纤光栅的传感特性进行了分析; (3)研究了基于长短双周期光纤光栅的温度、应变同时测量方法; (4)研究了基于长短双周期光纤光栅的多轴应变同时测量方法; (5)研究了基于长短双周期光纤光栅的编码波分复用技术。更多还原

【Abstract】 The fiber grating that used in fiber grating sensors mainly include Short-Period Fiber Grating(SPFG) and Long-Period Fiber Grating(LPFG). The grating called Short-Period Grating is ordinary equi-period Bragg grating(FBG). The Short-Period Grating has been utilized widely in sensing field, for its good sensing properties and mature demodulation technology. The Long-Period Grating has developed later than the Short-Period Grating, and has not utilized widely. But Long-Period Grating has its unique sensing properties, such as quite sensitive properties of strain, temperature and birefringence, sensitive to exterior medium. Because Long-Period Grating has those properties, more and more people paid their attention to the sensors based on it.The LPFG and SPFG are written in the same position of the fiber, and the new grating has the characteristics of the LPFG and SPFG. We called it as dual-period fiber grating (DPFG). The signal of the SPFG and the LPFG do not interfere each other. At the reflected end of the fiber, the signal of the SPFG can be detected only. But at the transmission end of the fiber, the signal of the both gratings can be detected. The transmission spectrum of the SPFG do not effect the measurement of the transmission spectrum of the LPFG. The paper researched the fabrication and the sensing properties of the DPFG, and discussed three application of the DPFG based on above research:1. the simultaneous measurement for the temperature and axial strain,2.the simultaneous measurement for multi-axial strain,3. the multiple wavelength techniques of encoding which based on DPFG.And the paper researched from theories and experiments on theabove three aspects.The contributions of this paper are:1.To research the fabrication of the DPFG,2. To analyse the sensing properties of the DPFG from theory,3. To research simultaneous measurement for the temperature and axial strain based on the DPFG,4. To research simultaneous measurement for multi-axial strain based on the DPFG,5. To research multiple wavelength techniques of encoding based on the DPFG.更多还原