Dual-detection-parameter SPR sensor based on graded index multimode fiber

Abstract

In this paper, a dual-detection-parameter SPR sensor for micro angle and micro displacement measurement was fabricated by using graded index multimode fiber. By employing mathematical modeling and theoretical simulation, the micro angle and micro displacement sensing properties of the graded index multimode fiber were studied and verified based on its special light transmission characteristics. The simulation results indicated that the total internal reflection angle (SPR incident angle) of the graded index multimode fiber was sensitive to the deviation angle and deviation displacement of the incident light. The experimental results showed that the wavelength sensitivity and light intensity sensitivity of the micro angle sensor was 2.417 nm/° and 0.236 a.u./°, respectively. And the wavelength sensitivity and light intensity sensitivity of the micro displacement sensor is 0.7084 nm/° and 0.0236 a.u./°, respectively. The dual-detection-parameter fiber SPR sensor is simple, stable and not easy to be damaged, which can be easily applied in various fields of micro angle and micro displacement measurement.