SNAP结构回音壁微腔的模式调控及其探针式微位移传感应用基础研究

The probe sensor of micro-displacement, which is a key component of the measurement system for microstructure with high aspect ratio, has been widely used in the fields of aerospace and nano-lithography. It’s difficult for the existing probe sensors based on CCD imaging and fiber grating demodulation to realize a large axial measuring range. The surface nano-scale axial photonics (SNAP) micro-resonator has a unique advantage in the field of probe sensing of micro-displacement due to its large axial distribution range of the mode field and convenience of making probe. Therefore, this project focusing on the research of micro-displacement sensing based on SNAP micro-resonator, aims at developing a novel probe sensor of micro-displacement with large range and high resolution. This project studies the mode regulation mechanism of SNAP micro-resonator and gives the basis of the shape optimization design. On the basis of the mode regulation mechanism, the theory model of displacement sensing will be established. Furthermore, the design criterion of the displacement sensor system will be given. The formation mechanism of SNAP micro-resonator in arc discharge machning is studied to obtain the controllable processing of micro-resonator’s shape. Implementation of this project can provide new thoughts and solutions for the design of the probe sensor of micro-displacement, and further lay theoretical and technical basis for the subsequent application of displacement sensor. This project can also provide shape design basis and processing technology guidance for other applications of SNAP micro-resonator, and further promote the development of SNAP micro-resonator research.

探针式微位移传感器作为微深内结构测量系统的关键器件，在航空航天和纳米光刻等领域的应用和需求日益广泛。现有基于CCD成像和光纤光栅解调等方案的位移传感探针难以实现轴向的大量程，而表面纳米轴向光子（SNAP）结构微腔具有模式场轴向分布范围广、易于做成探针的优点，在探针式微位移传感领域具有独特优势，因而本项目致力于SNAP微腔的微位移传感应用基础研究，旨在开发一种新型的大量程、高精度探针式微位移传感方法。本项目研究SNAP微腔的模式调控机理，给出其形状优化设计依据；构建基于多阶轴向模式联合解算的位移传感理论模型，提出传感系统的设计准则；研究电弧放电加工的SNAP微腔形成机理，实现微腔形状的可控加工。本项目的实施不仅可以为探针式微位移传感系统的设计提供新的思路和解决方法，给后续应用奠定理论和技术基础，还可以为SNAP微腔的其他应用提供形状设计依据和加工工艺指导，促进SNAP微腔研究领域的发展。

本项目通过对SNAP结构微腔-锥形光纤耦合系统的特性研究，开发了一种新型的大量程、高分辨率微位移传感系统。主要研究成果包括：1. 建立了SNAP结构微腔的模式场和谐振谱计算理论模型，计算分析了不同ERV轮廓和耦合参数对SNAP结构微腔模式谱的影响规律；2.通过控制耦合区域锥形光纤的尺寸，实现了SNAP结构微腔的洛伦兹、Fano和EIT三种不同线型特征谐振模式的激发，验证了SNAP微腔的模式调控规律；3. 建立了基于SNAP结构微腔多阶轴向模式联合解算的微位移传感模型，基于透过率的理论表达式，通过设置各阶模式的合适阈值，对微腔的位置进行编码，实现了位移解算。本项目还拓展研究了：1.基于SNAP结构微腔阵列的大量程位移传感技术；2.利用多阶轴向模式实现位移传感的信号解调新方法，包括条形码技术解调方案和人工神经网络解调技术，理论上均实现了20nm的位移传感分辨率。本项目的成果为探针式微位移传感系统的设计提供了新的思路和解决方法。