光子晶体光纤光栅传感机理及其在锚杆应力应变监测中的应用研究

Bolting is the most common supporting method in coal mine. Traditional electricity-based monitoring techniques are more subject to the environment disturbances and cannot monitor the real-time intra-force changes and realize remote data transmission. The project significantly improves the technical capacity to predict mine disaster warning by synthesizing the tunable characteristic of random fiber laser and free design of photonic crystal structure to monitor the stress-strain. Based on the coupled-mode theory, a new model for stress-strain analysis is established to study the transmission characteristics and sensing mechanism of photonic crystal fiber grating by merging the structure optimization design of photonic crystal into the transmission control mechanism. The beam-coupling mechanism and key factor which affect the sensing characteristic would be discussed carefully. Combined with the stress transfer mechanism between fiber Bragg grating and structure, the stability control method of strain transfer can be obtained. In order to solve the key techniques of long range and accuracy light source of sensors, the tuning mechanism of random fiber laser output is researched. By setting up appropriate bolting monitoring system, the relation between photonic crystal structure and stress-strain monitoring is established and provide a scientific basis for assessing stability and security.

锚杆作为矿山巷道的主要支护形式，常用的电类传感监测技术易受环境干扰且难以实现对其内部应力应变的实时监测及远程数据传输。本项目将随机光纤激光独特的可调谐特性与光子晶体结构的优化设计结合应用到应力应变监测，大幅提高了煤矿灾害预知预警的技术能力。基于耦合模理论建立光子晶体光纤光栅应力-应变传感分析模型，融合光子晶体结构优化设计和光波传输控制机制研究其传输特性和传感机理，着重分析光波耦合形成机制和影响传感特性的关键因素。结合光纤光栅与结构基体之间应力传递机理，获取锚杆应变传递的稳定性控制方法。探索随机光纤激光输出的可调谐机理，解决长距离、高精度顶板应力-应变监测中传感光源复用关键技术。搭建合适的锚杆监测系统测试实验平台，建立起光子晶体结构、光栅参量同应力-应变监测量的密切联系，为顶板的稳定程度和安全性评估提供科学依据。

本项目拟将光子晶体结构的优化设计结合 直接应用到顶板的应力-应变监测，重点对光子晶体光纤传输特性和传感光源的可调谐特性进行了研究，为基于光子晶体光纤光栅的安全监测系统设计提供充分的理论和实验基础。研究内容主要包括：基于光子晶体波导结构研究应力传感机理，融合光子晶体结构优化设计和光波传输控制机制，掌握光子晶体光纤应力传感分析方法；基于耦合模理论研究光子晶体光纤光栅应力传感机理，重点分析光波耦合形成机制和影响光纤传感特性的关键因素；探索多参量解调方法与温度补偿技术，实现温度不敏感的应力监测；基于激光与物质的相互作用机理，调控传感光源输出波长与光纤光栅中心波长匹配；进一步拓展到光子晶体光纤SPR传感领域，研究其应力传感特性并验证了可行性；最后设计多通道可调谐激光实验系统和激光器参数测试系统，应用于应力应变监测实验平台。本项目的研究能进一步完善光子晶体光纤传感理论，促进光纤传感器设计原理与实验手段的完善，为顶板的稳定程度和安全性评估提供科学依据。