光子晶体长周期光纤光栅局域耦合模理论研究

发布时间：2018-02-05 04:00

本文关键词： 局域耦合模理论光子晶体光纤长周期光纤光栅耦合模理论温度　出处：《中国计量学院》2016年硕士论文　论文类型：学位论文

【摘要】：光子晶体光纤跟普通光纤相比,具有许多独特的光纤特性。光子晶体光纤长周期光栅比普通光栅具有更多的优势,自问世以来一直备受相关行业关注。本文主要研究了光子晶体光纤长周期光栅的耦合机理和传输特性,为其制备提供了理论基础;并对长周期光纤光栅的温度不敏感封装进行了研究。本文主要研究内容如下:1.研究长周期光纤光栅理论建模的分析方法:传统耦合模理论和局域耦合模理论,并分析了传统耦合模理论的局限性:只对弱折射率调制且光纤没有形变的光栅适用。并详细介绍了对激光器制热法刻制的光子晶体光纤长周期光栅传输特性的计算流程。2.构建光子晶体光纤长周期光栅理论模型,用有限元法将栅区各个部分的模场分布以及计算各个模式的有效折射率,更直观的看到经过栅区后各个模式的变化情况。对LP01和LP11以及LP01和LP02的耦合进行了分析,并得到最终的传输谱,实现了数值模拟的过程。并用传统耦合模理论,在考虑结构形变的情况下对同一种光栅也进行了模拟,并与局域耦合模理论进行对比。3.从光子晶体光纤长周期光栅的制作方向考虑,研究在不同栅格个数、栅格周期和光栅栅区塌陷程度下,谐振波长的改变情况及其变化规律。在用激光器刻制光纤光栅的时候,曝光强度的调节决定着栅区的塌陷深度。本文详尽地研究了栅区塌陷程度对谐振波长和谐振深度的影响。研究结果表明,随着栅格个数的增加,谐振波长保持不变,透射峰深度增加;随着栅格周期的增加,谐振波长蓝移;随着光栅栅区塌陷程度的增加,谐振波长红移。4.采用有机玻璃作为封装材料对长周期光纤光栅做了封装性实验,自由状态下的长周期光纤光栅波长随温度变化的测量结果表明,随着温度的升高,谐振波长红移,温度灵敏度较高,波长与温度成线性关系;封装之后的长周期光纤光栅波长随温度变化的测量结果表明,其波长受温度的影响大大减小,漂移程度也相应地减小,而波长与温度仍然成线性关系。本次实验采用有机玻璃作为封装材料能有效的达到了保持长周期光纤光栅滤波器稳定性的效果。
[Abstract]:Compared with ordinary fiber, photonic crystal fiber (PCF) has many unique properties, and PCF long period grating has more advantages than ordinary grating. The coupling mechanism and transmission characteristics of photonic crystal fiber long period grating have been studied in this paper, which provides a theoretical basis for its fabrication. The temperature insensitive packaging of long-period fiber gratings is studied. The main contents of this thesis are as follows: 1. The theoretical modeling method of long-period fiber gratings is studied. Traditional coupled mode theory and local coupled mode theory. The limitations of the traditional coupled mode theory are also analyzed. It is only applicable to the grating with weak refractive index modulation and no distortion. The calculation flow of the propagation characteristics of photonic crystal fiber long period grating prepared by laser heating method is introduced in detail. 2. The long cycle of photonic crystal fiber is constructed. Period grating theoretical model. The mode field distribution of each part of the grid region and the effective refractive index of each mode are calculated by the finite element method. The LP01 and LP11 and the coupling of LP01 and LP02 are analyzed, and the final transmission spectrum is obtained. The process of numerical simulation is realized, and the same grating is simulated under the consideration of structural deformation by using the traditional coupled mode theory. And compared with the local coupled mode theory. 3. Considering the fabrication direction of photonic crystal fiber long period grating, we study the different grid number, grid period and grating area collapse degree. The variation of the resonant wavelength and its regularity, when the fiber grating is fabricated with a laser. The influence of the collapse degree of the gate on the resonant wavelength and the resonant depth is studied in detail. The results show that the number of grids increases with the increase of the number of grids. The resonant wavelength remains constant and the transmission peak depth increases. With the increase of grid period, the resonant wavelength is blue-shifted. With the increase of the collapse degree of grating gate, the resonant wavelength shift. 4. Using plexiglass as packaging material, the encapsulation experiment of long-period fiber grating is done. The measurement results of the wavelength of the long-period fiber grating in free state show that the resonant wavelength is red-shifted with the increase of temperature and the temperature sensitivity is high. The relationship between the wavelength and temperature is linear. The measurement results of the wavelength of the long-period fiber grating after encapsulation show that the wavelength is greatly affected by the temperature and the drift degree is also reduced accordingly. However, the wavelength and temperature are still linear. In this experiment, the stability of long period fiber grating filter can be effectively maintained by using organic glass as encapsulation material.
【学位授予单位】：中国计量学院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN253

【相似文献】