We present a novel D-shaped photonic crystal fiber sensor with double loss peaks based on surface plasmon resonance. The proposed sensor has a lot of better characteristics for refractive index detection compared with single-peak sensor. It is worth noting that the trough of the loss spectrum keeps unchanged as the analyte refractive index increases, which indicates that this sensor is extremely stable. In addition, numerical simulation shows that the average wavelength sensitivity can reach 29,000 nm/RIU and the maximum resolution is as high as 3.45 × 10⁻⁵ RIU. Furthermore, the coupling theory between fundamental mode and the surface plasmon polarization (SPP) mode is investigated in this paper. It is found that there is obvious competition between the resonant modes. This study has enlightening significance for us to understand the generation mechanism of polarization-entangled quantum photo source.

我们提出了一种新型的D形光子晶体光纤传感器，该传感器具有基于表面等离子体激元共振的双损失峰。所提出的传感器与单峰传感器相比具有许多更好的折射率检测特性。值得注意的是，随着分析物折射率的增加，损耗谱的谷值保持不变，这表明该传感器非常稳定。另外，数值模拟表明平均波长灵敏度可以达到29,000 nm / RIU，最大分辨率高达3.45×10 ^-5RIU。此外，本文研究了基本模式与表面等离子体激元极化（SPP）模式之间的耦合理论。发现谐振模式之间存在明显的竞争。这项研究对我们理解偏振纠缠量子光源的产生机理具有启发意义。