摘要
The difficulty with fiber cladding Surface Plasmon Resonance (SPR) sensors lies in coupling the core mode to the cladding mode without removing the cladding. This paper hereby endeavors to demonstrate a fiber cladding SPR sensor based on V-grooves structure by using a CO2 laser. V-grooves are engraved on single-mode fiber, step-index multimode fiber, and graded-index multimode fiber. When the transmitted light reaches the V-grooves structure, the higher-order cladding mode is excited, and a metal film is coated on the 2 cm cladding area after the V-grooves to form fiber cladding SPR sensors. This paper investigates the refractive index and bending sensing of V-groove cladding SPR sensors of single-mode, graded-index multimode, and step-index multimode fibers. The experimental results show that: the refractive index sensitivity of three kinds of sensors is 2811.34 nm/RIU, 1862.33 nm/RIU, and 1418.85 nm/RIU, respectively, and the curvature sensitivity of three types of sensors is 0.42 nm/m(-1), 1.03 nm/m(-1), and -6.59 nm/m(-1), respectively. The proposed sensors in this paper are easy to manufacture, demonstrate quality of high sensitivity, and can be applied extensively.
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单位哈尔滨工程大学; y