基于Bloch表面波的折射率传感器性能调控与机理研究

光学折射率传感器在医学、环境监测、食品安全、国防工业等领域具有重要应用价值，是微量生化组分实时、免标记检测中的主流技术。由复合光子晶体结构激发的Bloch表面波具有高品质因子、强场局域、双偏振激发等优势，将其作为折射率传感器探测信号势必会大幅提升折射率传感器之传感性能。本项目拟开展基于光栅耦合一维光子晶体结构激发的Bloch表面波折射率传感器的性能调控与机理研究，旨在为高性能、小型化、低吸收的折射率传感器的设计和制备提供帮助。利用Bloch波展开法求解传感器界面阻抗，利用严格耦合波分析法求解探测信号反射谱，根据它们的对应关系揭示Bloch表面波的激发条件与机理。再根据Bloch表面波激发条件探究Bloch表面波品质因子和传感器灵敏度的主次要影响因素，分析出对品质因子和灵敏度响应差异较大的变量（理想变量）用于折射率传感器的性能调控，通过调节理想变量给出提升折射率传感器性能的基本设计准则。

Optical refractive index sensor has important application value in medical science, environmental monitoring, food safety, national defense industry and other fields. It is the mainstream technology in real-time, label free detection of micro biochemical components. Bloch surface wave excited by composite photonic crystal structure has the advantages of high-quality factor, strong field localization and dual polarization excitation. Using Bloch surface wave as the detection signal of refractive index sensor will greatly improve the sensing performance of refractive index sensor. This project intends to carry out the performance control and mechanism research of Bloch surface wave refractive index sensor based on grating coupled one-dimensional photonic crystal structure excitation, the purpose is to provide help for the design and fabrication of high performance, miniaturization and low absorption refractive index sensor. The Bloch wave expansion method is used to solve the interface impedance of the sensor, and the rigorous coupled wave analysis method is used to solve the reflection spectrum of the detection signal. According to the corresponding relationship, the excitation condition and mechanism of Bloch surface wave are revealed. Then, according to the excitation conditions of Bloch surface wave, the main and secondary factors of Bloch surface wave quality factor and sensor sensitivity are studied. The variables (ideal variables) with great difference in response to quality factor and sensitivity are analyzed for the performance control of refractive index sensor. By adjusting the ideal variables, the basic design criteria to improve the performance of the refractive index sensor are given.