设计了一种双通道表面等离子体共振光纤传感器, 分析了Au、Cu两种材料对波长调制型表面等离子体共振光纤传感器的影响, 优化了金属厚度并且选取优化后的金属厚度dAu=47 nm, dCu=53 nm进行数值仿真分析。结果表明, 金属层为金的通道比金属层为铜的通道灵敏度高,但是金属层为铜的通道比金属层为金的通道检测精度高4倍; 金属层为金的传感通道适合检测折射率较低的物质, 而金属层为铜的传感通道适合检测折射率较高的物质, 该传感器的提出扩大了单一传感器的应用范围, 并且文中提出的传感器比传统的SPR传感器检测精度高, 灵敏度和单通道传感器一样。

A two-channel fiber optic sensor based on surface plasmon resonance was developed. The effects of two materials of Au and Cu on the performances of the fiber optic sensor modulated by incident wavelength were analyzed. The thickness of metal was optimized, and the optimized thickness of the metal dAu=47 nm and dCu=53 nm was chosen to carry out numerical simulation. And the results show that, the sensitivity of the channel of Au is higher than the sensitivity of the channel of Cu, on the other hand, the detection precision of the channel of Cu is four times higher than the detection precision of the channel of Au. The sensing channel of Au is suitable for the detection of the lower refractive index of sensing medium, and the sensing channel of Cu is suitable for the detection of higher refractive index of sensing medium. The proposed sensor has expanded the detection range, compared with the single channel sensor. The detection accuracy of the two-channel SPR fiber sensor is higher than that of the single channel sensor. The measuring sensitivities of two-channel SPR fiber sensor and conventional single channel sensor are the same.