Fiber SPR two-dimensional micro displacement sensor based on the coaxial double waveguide with a conical structure

Fiber SPR micro displacement sensor cannot be used for two-dimensional displacement sensing at present. In this paper, we proposed and demonstrated a fiber SPR two-dimensional micro displacement sensor based on the coaxial double waveguide with a conical structure. The coaxial double waveguide is fused into a cone as the light injection fiber, and two different forms of outgoing light fields can be obtained through two cores of the fiber. The horn shaped light field emitted by the ring core of the coaxial double waveguide can cooperate with the sensing fiber to realize the micro displacement sensing in the x-axis direction. And the straight beam emitted by the middle core of the coaxial double waveguide can cooperate with the sensing fiber to realize the micro displacement sensing in the y-axis direction. Through simulation analysis and experimental test, its average wavelength sensitivity and light intensity sensitivity of the x-axis displacement are 0.0537nm/mu m and 0.000124a.u./mu m, respectively. And that of the y-axis displacement are 0.315nm/mu m and 0.00277a.u./mu m, respectively. The proposed fiber sensor realizes the two-dimensional displacement sensing based on SPR, which can be widely used in the fields of two-dimensional micro displacement measurement and two-dimensional position precision positioning. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

This paper proposes a fiber SPR two-dimensional micro displacement sensor based on a coaxial double waveguide with a conical structure. The sensor achieves micro displacement sensing in the x-axis and y-axis directions through the coordination of different light fields emitted by the waveguide and the sensing fiber. The simulation and experimental results demonstrate the high sensitivity and effectiveness of this sensor.