磁流体选择填充微结构光纤的设计、制备及性能研究

The photonic device based on the microstructure optical fiber infiltrated with functional materials, combining the physical effects of functional materials under external fields with the fiber microstructure, shows advantages of flexibility in design, tunability under external fields, easy to integration and all in fiber. As a new type of photoelectric functional material, magnetic fluid has the property of refractive index adjustable, birefringence, dichroism, magnetic dispersion, Faraday effect, field dependent transmission and superparamagnetism. It provides a new carrier and breakthrough for the study on microstructure optical fiber infiltrated with functional materials. In this project, the microstructure optical fiber selectively infiltrated with magnetic fluid (MFMOF) which shows superior performance is to be designed based on the theory of optical waveguide and the finite element method. By utilizing microscope technology to control probe movement accurately and UV glue curing functions, the microstructure optical fiber air holes will be plugged selectively. The relationships between infilling parameters such as pressure, temperature, fiber structure and infilling rate, length in the magnetic fluid infilling process will be established. The MFMOF will then be fabricated. The characteristics of MFMOF, such as loss, polarization, modes coupling and filtering, will be measured in this project. The mechanism and characteristics of resonance between core modes and defect modes in the MFMOF will be revealed by the combination of theory and experiment results. Based on the research of MFMOF, it is expected to deepen the understanding of the interaction between functional materials, micro-nano medium and lights. This project will lay the foundation for the application of magnetic fluid infilling microstructure fibers in modulator, sensor, filter and optical switch.

基于功能材料填充的微结构光纤光子器件将功能材料的物理效应与光纤微纳结构相结合，具有设计灵活、外场调谐、易于集成和全光纤化等优点。磁流体作为一种新型光电功能材料，具有折射率可调、双折射、二向色性、磁色散、法拉第效应、场依赖传输和超顺磁性等特点，为功能材料填充微结构光纤的研究提供了新的载体和突破点。本项目以光波导理论为基础，结合有限元法模拟并设计具有优异性能的磁流体选择填充微结构光纤（MFMOF）；利用显微技术精确控制探针移动及紫外胶固化功能，选择性封堵光纤空气孔；建立磁流体填充过程中压力、温度、气孔尺度等与填充速率、填充长度的关系，制备MFMOF；测试MFMOF的损耗、偏振、模式耦合和滤波等特性，理论与实验相结合揭示纤芯模与缺陷模共振产生的机理和特点。MFMOF的研究有望深化人们对光与功能材料、微纳介质相互作用的理解，为磁流体填充微结构光纤在调制器、传感器、滤波器及光开关等中的应用奠定基础。

本项目对磁流体填充微结构光纤的优化设计、填充方法、传感机理等进行了研究。利用微加工平台和飞秒激光技术实现了在微结构光纤中选择填充磁流体溶液。在此基础上，研究了微结构光纤中光纤结构参数对纤芯模和磁流体缺陷模间耦合特性的影响机理；研究了磁流体填充孔对双芯微结构光纤中超模耦合特性的影响机理；研究了磁流体微结构光纤对萨格奈克干涉仪中输出谱的影响机理。在磁流体微结构光纤嵌入的萨格奈克干涉仪中，通过磁场对磁流体双折射的影响，同时研究了磁场强度和方向对萨格奈克干涉仪中输出谱的影响机理，实现了对磁场矢量的测量。通过以上对磁流体填充微结构光纤的研究实现了磁场对微结构光纤中磁流体缺陷模的模式有效折射率，以及纤芯传输模的有效折射率的调控。通过优化微结构光纤结构参数及磁流体填充分布，获取了高灵敏度的磁场强度及矢量传感器。通过该项目的实施深化了人们对光与微纳波导、功能材料之间相互作用的认识，为磁流体微结构光纤在磁场传感、光开关、滤波器等中的应用提供了重要的理论依据。