Dual-core fiber curvature sensor based on femtosecond laser processing
Year: 2025
Type: article
Abstract: In this paper, a curvature sensor based on femtosecond laser processing of two-core fiber is proposed. The sensor uses the interference between two core modes of the two-core fiber to realize curvature sensing. According to the two-beam interference formula, the curvature sensing sensitivity and the free spectral range of the sensing structure are theoretically independent and adjustable, consequently it is more flexible. The sensor comprises single-mode fiber, no-core fiber, and two-core fiber. Femtosecond laser fabricates waveguides in no-core fiber to guide light from single-mode fiber into a two-core fiber. In order to construct the optical path difference, the end face of the two-core fiber is processed into a stepped shape using the femtosecond laser. The entire fiber structure constitutes the MI. The curvature tests of this sensor are carried out. The experimental results demonstrate that the sensor can identify a one-dimensional bending direction. Curvature is applied to the two-core fiber of different lengths. It is found that the longer the length of the bending part, the higher the sensor’s sensitivity. When the bending part of the two-core fiber is 4 cm, in the curvature range of 0 to 0.241 m −1 , the curvature sensitivity of the sensor bending in different directions can reach −60.4 nm/m −1 and +60.1 nm/m −1 , while maintaining high linearity.
Source: Optical Fiber Technology
Authors: Bo-yuan Wang, Zhen-yu Yuan, Shuai-ke Li, Yu-dong Li
Institution: Northeastern University
Language: English
Topic: Advanced Fiber Optic Sensors
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,360
OpenAlex ID: W4410708133