Research on SPR Two-Parameter PCF Sensing Technology Based on U-Shaped Nanowires

To solve the problem that the band of optical fiber sensor is relatively close and the sensitivity is low when measuring refractive index/temperature simultaneously, Photonic crystal fiber (PCF) sensors based on U-groove nanowires are proposed in this paper. The refractive index and temperature were measured simultaneously by the U-shaped gold nanowire and semi-arc gold film channels. The finite element method analyzed the spectral response characteristics of the two-parameter sensor. In terms of optimization, the influence of metal parameters (gold wire and gold film part) and optical fiber structure (polishing depth and groove width) on absorption peak is discussed, and the optimal parameters are determined. The results show that the maximum sensitivity of the two-parameter sensor in the refractive index range of 1.35-1.43 and the temperature range of 20°C-40°C is as high as 12300nm/RIU and 1.56nm/°C, and the operating range of the two-parameter band is more than 200 nm. This two-parameter sensing structure based on a U-shaped nanowire structure not only has high sensitivity and strong anti-interference but can also solve the cross-sensitivity problem, which provides a new idea for applying the two-parameter optical fiber sensing field.