重叠级联长周期光纤光栅理论及应用研究

发布时间：2018-05-26 12:57

本文选题：重叠级联长周期光纤光栅 + 谐振波长　；参考：《北京交通大学》2015年硕士论文

【摘要】：长周期光纤光栅由于具有制作成本低、精度易控制,没有后向反射,对多个环境参量敏感等优点,在多种光器件的制作中发挥着重要的作用,一直以来都是光通信和光传感等领域的研究热点之一。级联长周期光纤光栅作为长周期光纤光栅的特殊形式,其透射谱和单个长周期光纤光栅透射谱相比控制更加灵活,具有更为广泛的应用前景。本论文从理论研究和仿真分析两个方面开展了重叠级联长周期光纤光栅的特性及应用研究,所取得的主要进展及完成工作如下： (1)从光纤的基本理论出发,利用三层介质光纤模型,对重叠级联长周期光纤光栅的纤芯模和包层模的有效折射率及耦合常数进行了求解,分析了重叠级联长周期光纤光栅的模式耦合原理,进而利用数值模拟得到了重叠级联两个长周期光纤光栅的透射谱。 (2)分析了重叠级联长周期光纤光栅的带阻滤波特性,通过实验仿真探讨了纤芯模和包层模的耦合常数、用于级联的长周期光纤光栅的周期及光栅长度对滤波性能的影响,为优化设计重叠级联长周期光纤光栅参数,实现理想的带阻滤波性能提供了一定的指导。 (3)研究了重叠级联长周期光纤光栅的环境折射率探测特性,分析了长周期光纤光栅的谐振波长与光栅周期的关系。研究结果表明谐振波长位置不同,其随环境折射率变化而发生漂移的方向也不同。优化设计了包层模次及对应谐振波长的选择,实现重叠级联长周期光纤光栅的高灵敏度环境折射率的测量,研究结果表明其环境折射率在1.3～1.42区间的检测灵敏度高达546nm/RIU～2187nm/RIU。
[Abstract]:Long period fiber grating (LPFG) plays an important role in the fabrication of many optical devices due to its advantages of low cost, easy control of precision, no backward reflection, sensitivity to many environmental parameters, and so on. It has always been one of the research hotspots in the field of optical communication and optical sensing. As a special form of long-period fiber grating, cascaded long-period fiber grating has a more flexible control of transmission spectrum than a single long-period fiber grating, and has a more extensive application prospect. In this thesis, the characteristics and applications of overlapping cascaded long-period fiber gratings are studied from two aspects: theoretical research and simulation analysis. The main progress and the work accomplished are as follows: 1) based on the basic theory of fiber, the effective refractive index and coupling constant of core mode and cladding mode of overlapping cascaded long-period fiber grating are solved by using three-layer dielectric fiber model. The mode coupling principle of overlapping cascaded long-period fiber gratings is analyzed, and the transmission spectra of overlapping cascaded long-period fiber gratings are obtained by numerical simulation. (2) the band-stop filtering characteristics of overlapping cascaded long-period fiber gratings are analyzed. The coupling constants of core mode and cladding mode are discussed through experimental simulation. The period of cascaded long-period fiber gratings and the influence of grating length on filtering performance are discussed. It provides some guidance for optimizing the design parameters of overlapping cascaded long-period fiber gratings and realizing the ideal band-stop filtering performance. The environmental refractive index detection characteristics of overlapped cascaded long-period fiber gratings are studied. The relationship between the resonant wavelength of long-period fiber gratings and the grating period is analyzed. The results show that the position of resonant wavelength is different and the drift direction is different with the change of environmental refractive index. The selection of cladding modes and corresponding resonant wavelengths is optimized to measure the highly sensitive ambient refractive index of overlapping cascaded long-period fiber gratings. The results show that the detection sensitivity of the ambient refractive index is as high as 546nm / r RIU2187nmP RIU in the range of 1.3nm1.42.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN253

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