98%
921
2 minutes
20
An optical frequency domain reflectometry (OFDR) shape sensor was demonstrated based on a femtosecond-laser-inscribed weak fiber Bragg grating (WFBG) array in a multicore fiber (MCF). A WFBG array consisting of 60 identical WFBGs was successfully inscribed in each core along a 60 cm long MCF using the femtosecond-laser point-by-point technology, where the length and space of each WFBG were 2 and 8 mm, respectively. The strain distribution of each core in two-dimensional (2D) and three-dimensional (3D) shape sensing was successfully demodulated using the traditional cross correlation algorithm, attributed to the accurate localization of each WFBG. The minimum reconstruction error per unit length of the 2D and 3D shape sensors has been improved to 1.08% and 1.07%, respectively, using the apparent curvature vector method based on the Bishop frame.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/OL.516067 | DOI Listing |
A compact high-resolution distributed liquid refractive index (RI) sensor based on the side-polished D-shaped fiber (DSF) that needs no post-fabrication modifications is presented. Since phase demodulation can offer better sensing resolution than most traditional amplitude cross-correlation algorithms, for what we believe to be the first time, we propose and experimentally investigate the integration of phase-based optical frequency domain reflectometry (φ-OFDR) with a DSF in its bare state and as fabricated for liquid RI monitoring. The principle of refractive index measurement by phase tracking in φ-OFDR is described with an explanation of the data processing algorithm.
View Article and Find Full Text PDFWhat we believe to be a novel wavelength shift demodulation method for optical frequency domain reflectometry (OFDR), i.e., adaptive spectrum method (ASM), was proposed and demonstrated to achieve high-spatial-resolution two-dimensional (2D) shape sensing with a narrow sweep range.
View Article and Find Full Text PDFOpt Express
April 2025
In optical fiber shape sensing technology, enhancing sensing accuracy while simultaneously achieving real-time shape reconstruction presents a notable challenge. This work presents a fast strain demodulation algorithm for the optical frequency domain reflectometry (OFDR) shape sensing system. The fast strain demodulation algorithm comprises deviation calculation and deviation denoising for shape-sensing convolutional neural network (DDSSnet).
View Article and Find Full Text PDFSensors (Basel)
January 2025
State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China.
Water pipelines in water diversion projects can leak, leading to soil deformation and ground subsidence, necessitating research into soil deformation monitoring technology. This study conducted model tests to monitor soil deformation around leaking buried water pipelines using distributed fiber optic strain sensing (DFOSS) technology based on optical frequency domain reflectometry (OFDR). By arranging strain measurement fibers in a pipe-soil model, we investigated how leak location, leak size, pipe burial depth, and water flow velocity affect soil strain field monitoring results.
View Article and Find Full Text PDFIEEE Int Conf Robot Autom
May 2024
Department of Computer and Software Engineering, Polytechnique Montréal, Montréal, QC H3T1J4, Canada.
In minimally invasive procedures such as biopsies and prostate cancer brachytherapy, accurate needle placement remains challenging due to limitations in current tracking methods related to interference, reliability, resolution or image contrast. This often leads to frequent needle adjustments and reinsertions. To address these shortcomings, we introduce an optimized needle shape-sensing method using a fully distributed grating-based sensor.
View Article and Find Full Text PDF