电场诱导可编程长周期液晶光纤光栅制备及特性研究

Long-period fiber gratings (LPGs) as high performance filters have been widely applied in optical fiber communications and sensing fields. In general, fiber gratings are formed in solid fiber materials, once a LPG is formed, it is hard to controllable operate the refractive index modulation of the grating, which will affect the adjustment of the transmission characteristics of the grating. Additionally, the limited adjusting range will also restrict the LPGs performance. Therefore, it is necessary to explore a LPG structure with rewrite and programmable characteristics to improve the ability of dynamic filtering..This project proposes to combine with micro-structured fiber and the electrooptical effect of liquid crystal to research the mechanism and preparation method of the electric field-induced liquid crystal LPGs. The orientation of the liquid crystal molecular will be subjected to the perturbations from the electric field, the dynamic regulation of the refractive index modulation can be realized by controlling the intensity and distribution of the electric field by the programmable array electrodes, finally, the transmission characteristics of the liquid crystal LPGs can be flexibly controlled. The mechanism of the liquid crystal-based long period fiber grating will be explored. The variation law of the orientation of liquid crystal and the electric field intensity and the relationship between the electric field intensity and liquid crystal refractive index will be investigated, and the refractive index modulation depth of the liquid crystal long-period fiber grating can be calculated, and the electric field-induced re-write liquid crystal LPGs with programmable properties will be designed by tuning and optimizing the geometry parameters of the grating structure. This project will lay a solid foundation for the development of the high-performance and controllable optoelectronic devices.

长周期光纤光栅作为一种高性能滤波器件，在光纤通信和光纤传感领域得到了广泛应用。通常，光纤光栅是在光纤材料中形成，一旦形成很难再对光栅折射率调制进行可控性操作，这影响了光栅透射特性的调节，同时也限制其性能的发挥；因此，探索具有再写和编程特性的长周期光纤光栅来提高动态滤波能力显得尤为重要。.本项目拟以微结构光纤为载体，结合液晶的电光特性，研究基于电场调控成栅机理的长周期液晶光纤光栅的制备方法，由于液晶分子取向易受电场的扰动，因此通过可编程阵列电极控制电场强度和分布，可实现光栅折射率调制的动态调谐及传输特性的灵活控制；通过理论与实验，探究液晶长周期光纤光栅成栅机理，研究液晶晶向随电场强度的变化规律，分析电场强度与液晶折射率之间的关系，推算液晶长周期光纤光栅的调制深度；通过优化结构参数，设计出具有可编程特性、可再生的长周期液晶光纤光栅。本项目的实现将为研制高性能、可调控的光电子器件打下良好基础。

光纤光栅作为一种高性能滤波器件，在光纤通信和光纤传感领域得到了广泛应用。通常，光纤光栅是在光纤材料中形成，一旦形成很难再对光栅折射率调制进行可控性操作，这影响了光栅光谱特性的调节，同时也限制其性能的发挥；因此，探索具有可调光谱特性的光纤光栅来提高动态滤波能力显得尤为重要。本项目提出了基于微结构光纤的新型光电子功能器件及传感器件，利用新的光纤后处理及功能化方案，着力于光纤功能器件的设计与制备，并以提升光纤功能器件的性能为研究目标。研究内容主要包括：（1）提出了微结构光纤传导特性调控机制及方法，以及可用于微结构光纤性能调控的方法；（2）研究了基于声光效应的光纤光栅光谱特性调控，以及不同声波类型对光栅光谱特性的影响；（3）实现了基于微结构光纤的高性能光纤功能器件，以及不同的光纤器件功能化方案。本项目的实施将为实现高性能、可调的光电子器件制备与应用打下一定基础。