Zhengkun Wang, Zhinan Yu, Ning Wang, Yong Zhu, Jie Zhang
Opt Lett. 2021 Sep 1;46(17):4300-4303. doi: 10.1364/OL.435839.
A Raman sensor based on a cavity-enhanced Ag nanoparticle (AgNP) decorated tapered fiber is proposed. Its Raman enhancements are mainly caused by the localized surface plasmon resonance effect of AgNPs decorated on the tapered optical fiber surface and the further reflective laser excitation induced by the capillary-based reflective cavity. We theoretically investigate the backward Stokes power conversion efficiency and cavity enhancement factor of the sensor. The calculated relationship between the cavity enhancement factor and distance L from the tip to reflective rod is also discussed. Subsequently, the proving experiments were carried out for a tapered fiber surface-enhanced Raman scattering (SERS) probe and cavity-enhanced metal decorated tapered fiber Raman sensors. The analytical enhancement factor is 5.51×10 for the tapered fiber SERS probe. Moreover, the predicted curves of the theoretical model are close to the experimental values. This Letter provides a possible way to rigorously quantify the complete coupling efficiency for tapered fiber SERS probes, as well as cavity enhancement factors of cavity-enhanced Raman sensors.
提出了一种基于腔增强银纳米颗粒（AgNP）修饰的锥形光纤的拉曼传感器。其拉曼增强主要由修饰在锥形光纤表面的AgNP的局域表面等离子体共振效应以及基于毛细管的反射腔引起的进一步反射激光激发所致。我们从理论上研究了该传感器的后向斯托克斯功率转换效率和腔增强因子。还讨论了腔增强因子与从尖端到反射杆的距离L之间的计算关系。随后，对锥形光纤表面增强拉曼散射（SERS）探针和腔增强金属修饰的锥形光纤拉曼传感器进行了验证实验。锥形光纤SERS探针的分析增强因子为5.51×10。此外，理论模型的预测曲线与实验值接近。本文为严格量化锥形光纤SERS探针的完全耦合效率以及腔增强拉曼传感器的腔增强因子提供了一种可能的方法。
