基于U型结构的单模光纤SPR折射率传感器

发布时间：2019-04-02 03:21

【摘要】：设计了一种基于U型结构的单模光纤表面等离子体共振折射率传感器,采用在移除部分包层并弯曲成U型固定后的单模光纤表面镀金纳米层和TiO2调制层的方式,实现表面等离子体共振的激发.利用有限元仿真软件COMSOL Multiphysics,研究了不同弯曲半径和TiO2调制层厚度对传感性能的影响.通过对四种弯曲半径(R=0.3cm,0.5cm,0.8cm,1cm)的分析,结果表明随着弯曲半径增大,表面等离子体共振信号强度增大且峰值波长有微小的蓝移.在弯曲半径为0.5cm的条件下,研究了TiO2调制层厚度从0变化到40nm对传感器性能的影响,结果表明随着TiO2调制层厚度增大,表面等离子体共振峰峰值波长红移且对外界折射率变化的灵敏度显著增大.在弯曲半径为0.5cm,TiO2调制层厚度为40nm的条件下,传感器在低折射率区(nd=1.333)灵敏度达到了5 959nm/RIU,高折射率区(nd=1.383)灵敏度达到了11 092nm/RIU.与没有调制层的结果相比,灵敏度提高了一倍左右.
[Abstract]:A single-mode fiber surface plasmon resonance refractive index sensor based on U-shaped structure was designed. The gold-plated nano-layer and TiO2 modulation layer on the surface of single-mode fiber were fabricated by removing part of the cladding and bending into the U-shaped fixed surface. Surface plasmon resonance excitation is realized. The effects of different bending radius and the thickness of TiO2 modulation layer on the sensing performance are studied by using the finite element simulation software COMSOL Multiphysics,. Through the analysis of four bending radii (R = 0.3cm, 0.5cm, 0.8cm, 1cm), the results show that with the increase of bending radius, the intensity of surface plasmon resonance (SPR) signal increases and the peak wavelength has a small blue shift. When the bending radius is 0.5cm, the effect of the thickness of TiO2 modulation layer from 0 to 40nm on the performance of the sensor is studied. The results show that the thickness of TiO2 modulation layer increases with the increase of the thickness of the modulation layer. The peak wavelength of the surface plasma resonance peak is redshifted and the sensitivity to the change of external refractive index is significantly increased. When the bending radius is 0.5 cm and the thickness of TIO 2 modulation layer is 40nm, the sensitivity of the sensor in the low refractive region (nd=1.333) and the high refractive index region (nd=1.383) is 5 959 nm and 11 992 nm respectively, and the sensitivity of the sensor in the low refractive region (nd=1.333) is 5 959 nm and the sensitivity of the high index region (nd=1.383) is 11 992 nm. Compared with the results without modulation layer, the sensitivity is about doubled.
【作者单位】：天津大学精密仪器与光电子工程学院天津大学光纤传感研究所天津市光纤传感工程中心天津大学光电信息技术教育部重点实验室;
【基金】：国家自然科学基金(Nos.61108070,61227011,61378043,61475114) 国家仪器专项(No.2013YQ030915)资助~~
【分类号】：TP212

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