扫描激光多模光纤白光干涉测量术及蓝宝石光纤高温传感

The aim of this proposal is exploring and investigating techniques for the measurement of temperature, pressure, and strain under ultrahigh-temperature environment of 1000℃-1800℃. The properties of the sapphire fiber, such as enduring high temperature and good optical property, make it possible to be sculptured as a Fabry-Perot interferometer by using the femtosecond laser , in which there is only one material. However, the sapphire fiber is a multi-mode fiber, and the composed interferometric sensor is a multi-mode interferometer. The demodulation technique of the multi-mode interferometric sensor is quite different from a single-mode fiber based interferometric sensor. In this proposal, we will investigate the sculpture technique of femtosecond laser, and analyze the coupling between single-mode fiber and multi-mode fiber, multi-mode fiber and sapphire fiber. The multi-mode interference model will be established. We will also study the multi-mode Fourier transform white-light interferometry. Experimental tests for temperature, strain, and pressure under ultrahigh-temperature will be executed. The technique route for measurements under ultrahigh-temperature will be constructed. The research work will reserve the correspond techniques for national defense requirements.

本申请的目的是探索和研究超高温（1000℃-1800℃）恶劣环境下的温度、压力、应变等物理量的测量技术。利用蓝宝石光纤的熔点高（2045℃）、光学性能好的特点，研究利用飞秒激光雕刻的方法，在蓝宝石光纤末端加工出单一材料的全蓝宝石光纤法珀干涉仪，构成多种物理量光纤传感器。但蓝宝石光纤是多模光纤，以之构成的FP干涉型传感器是多模干涉仪，其信号解调技术不同于现有的方法。本申请将研究针对蓝宝石光纤的飞秒激光微纳加工工艺；分析和解决单模光纤与多模光纤、多模光纤与蓝宝石光纤的耦合问题；利用模式分析法建立蓝宝石光纤多模干涉理论模型；研究傅立叶变换多模光纤白光干涉测量术；在超高温环境下完成温度、压力、应变测量实验。最终形成超高温物理传感器的技术方案，为我国在更高温度环境下的测试测量储备技术，为尖端国防科技的进一步发展提供技术保障。

本课题探究了蓝宝石光纤传输损耗，与单模及光纤的耦合效率等特征参数，探究了蓝宝石光纤和石英光纤的熔接技术，成功研制出蓝宝石晶片高温温度传感器，并实现了在室温至1500℃下的实时温度测量，测量精度小于全量程的2%；研制出了蓝宝石光纤高温加速度传感器，实现了室温至600℃范围内的0-10g加速度测量，并且该传感器能承受1500℃的高温；研制了全蓝宝石结构的光纤高温温度传感器，实现了室温至1500℃的温度测量，测量精度小于全量程的2%。针对蓝宝石光纤传感器所产生的多模干涉信号解调问题，提出了一种归一化傅里叶变换解调算法，解调精度为0.05um，分辨率为1nm。同时针对蓝宝石光纤多模干涉信号的拾取，研制出了两种不同的高阶模抑制拾取技术，分别为类锥形石英光纤多级耦合技术和石英光纤锥形连接技术，极大的提高了蓝宝石光纤FP传感器干涉信号的质量，使得解调精度得以提高。本课题申请发明专利3项，授权3项，发表论文26篇，其中SCI收录20篇，会议特邀报告3次，培养博士研究生4人，硕士研究生10人。获教育部发明一等奖。研究成果在国防，航空航天领域得以应用，为多个国家重大项目提供了技术保障。