微波光子辅助的倾斜光纤光栅表面等离子体共振传感基础研究

With the rapid development of modern environmental monitoring and bio-chemical sensor industry, more and more attention has been paid to the disease detection and health protection. The requirements of research and development on the new type of high sensitivity, fast detection and low cost surface plasmon resonance (SPR) sensing technology that can be easily integrated with variety of technology has become especially intense. Compared with the optical demodulation approach adopted by traditional SPR sensing technologies, microwave demodulation method shows great potential in improving sensitivity, resolution and stability. By utilizing the periodic metal nanostructure layer coated tilted fiber Bragg grating (TFBG) enhanced local SPR and its generated narrow bandwidth frequency comb notch filtering, a novel communication band photonic assisted microwave demodulation approach for TFBG-SPR composite biochemical sensor is proposed in this project. Based on the establishment of the TFBG-SPR simulation model, this project focus on the study of the enhanced local SPR effects on the generated microwave frequency response of microwave photonic link and establish the mapping between the output microwave signal characteristics and the refractive index of the analyte. Finally, controllable fabrication processes of metal nanostructure layer coated TFBG is investigated to enable the microwave photonic assisted TFBG-SPR biosensor system with high sensitivity, fast and flexible detection, low cost and ease of integration.

随着环境监测、生化检测等行业的快速发展，人们愈来愈关注自身的健康检测与防护，研发复杂环境下对生化疾病等信息实施高灵敏度、灵活快速、低成本一体化的新型表面等离子体共振（SPR）传感技术的需求愈来愈强烈。相比于传统SPR传感技术采用的光学解调方式，微波解调方式在提高传感灵敏度、分辨率及稳定性等方面极具潜力。本项目基于周期性金属纳米结构薄膜涂覆的倾斜光纤光栅（TFBG）局域SPR场增强特性及其精细梳状窄带透射光谱，设计一种工作于通信波段的光学-微波融合的TFBG-SPR生化传感器。在建立TFBG-SPR仿真模型的基础上，研究金属纳米结构局域SPR场增强传感机制与微波光子链路输出微波信号频率响应及调谐范围的作用机理，建立输出微波信号特征与待测物折射率之间的映射，探索稳定可控的金属纳米结构薄膜涂覆的TFBG制备工艺，实现高灵敏度、快速灵活、低成本一体化的微波光子辅助TFBG-SPR生化传感系统。

随着科技的快速发展，研发能够在复杂环境下对生化疾病等信息实施高灵敏度、灵活快速、低成本一体化的新型表面等离子体共振传感技术的需求愈来愈强烈。本项目提出一种微波光子技术与倾斜光纤光栅相结合的传感方案，相比于传统传感技术采用的光学解调方式，微波解调方式在提高传感灵敏度、分辨率及稳定性等方面极具潜力。 项目重点围绕微波光学信号生成、基于倾斜光纤光栅的传感单元参数表征等关键科学问题开展探索与研究，建立了完备的理论解析模型，明晰了光子辅助的微波信号特征与待测物有效折射率之间的映射，实现了高灵敏度、灵活、快速、低成本的光子辅助微波传感技术。取得了如下研究成果：.（1）构建了完备的基于倾斜光栅光谱结构的微波光子滤波器系统模型，研究并探明了倾斜光栅光域频谱幅度、自由光谱范围、微波光调制与解调等过程对微波滤波器中心频率、工作带宽的作用机制，并实现了在5-14 GHz范围内可调谐的微波光子滤波器。（2）采用1530nm-1570nm的宽谱光源以及8度倾斜光纤光栅作为传感单元，实现了一种高灵敏度的微波光子传感解调系统。对温度及轴向应变两个环境参量分别做出了理论仿真及实验研究。现有实验条件下，该技术可实现温度传感灵敏度为1.2083 MHz/℃；轴向应变传感时，传感灵敏度为18.93 kHz/με。（3）完成了SPR的理论仿真研究，根据严格耦合波理论，使用商业模拟软件FDTD Solutions软件以及Matlab进行了金属纳米阵列传感器的设计以及性能分析。