螺旋形塑料光纤表面等离子体共振折射率传感器

Plasmon resonance refractive index sensor of spiral-shaped plastic optical fiber surface

研究了基于波长调制的螺旋形塑料光纤(plastic optical fiber, POF)表面等离子体共振(surface plasmon resonance, SPR)折射率传感器。采用机械热压和扭曲法将塑料光纤制备成螺旋形,在螺旋形POF上通过磁控溅射蒸镀一定厚度(约50 nm)的金属薄膜来激励SPR效应,从而形成螺旋形POF-SPR传感器。通过对螺旋形POF-SPR传感器的结构进行修饰,研究不同结构参数对折射率传感特性的影响。实验结果表明:由厚度为500μm扁平形POF扭制、螺纹数为4的螺旋形POF-SPR传感器具有较好的线性度和折射率传感特性,在折射率为1.335~1.400范围内测得的灵敏度为1 262 nm/RIU。该传感器具有成本较低、制备简单、结构稳定等优点。

A spiral-shaped plastic optical fiber(POF) surface plasmon resonance(SPR) refractive index sensor based on wavelength modulation was studied. First, the plastic optical fiber was prepared into a spiral by mechanical hot pressing and deforming method, and then a metal film with a certain thickness(about 50 nm)was deposited on the spiral-shaped POF by magnetron sputtering to stimulate the SPR effect, thereby forming a spiral-shaped POF-SPR sensor. By modifying the structure of the spiral-shaped POF-SPR sensor, the effects of different structural parameters on the refractive index sensing properties were studied. The experimental results show that the spiral-shaped POF-SPR sensor deforming from a flat POF with a thickness of 500 μm and a thread number of 4 has the better linearity and refractive index sensing characteristics, and the measured sensitivity in the refractive index range of 1.335~1.400 is 1 262 nm/RIU. The proposed sensor has the advantages of low cost, simple preparation and stable structure.