基于金属-介质-金属多层膜结构的空芯光纤折射率传感器

Refractive Index Sensor Based on Hollow Optical Fiber with Metal-Dielectric-Metal Multilayered Films Structure

提出了一种新型的基于金属-介质-金属的多层膜结构的空芯光纤折射率传感器,通过建立光学模型计算了该传感器的传输光谱。对介质膜材料分别为二氧化硅、环烯烃聚合物和碘化银时的传感器性能进行了分析。当空芯光纤内部检测液体折射率处于不同范围时,所设计的传感器分别利用导模共振、表面等离子体共振以及波导耦合表面等离子体共振的原理进行传感。相比于传统的空芯光纤传感器,所提的传感器不仅检测范围超大(1.3~1.64,几乎覆盖了全部液体介质的折射率)而且品质因数提高了一倍。

A new kind of refractive index sensor based on a hollow optical fiber with a metal-dielectric-metal multilayered films structure is proposed and its transmission spectrum is calculated by the establishment of an optical model.The performances are analyzed for the designed sensors with SiO2,cycloolefine polymer and AgI as the dielectric materials,respectively.When the refractive index of the detected liquid in the hollow optical fiber is in different ranges,the principles of the guided mode resonance,surface plasmon resonance（SPR）and waveguidecoupled SPR are employed for sensing by the designed sensor,respectively.Compared with the traditional hollow fiber sensors,the proposed sensor not only has a greatly extended detection range which is 1.3-1.64 and almost covers all the refractive indexes of liquids,but also its figure of merit is increased up to twice.