Research and assessment of high sensitivity intensity modulation vector curvature sensor based on cascaded bamboo-joint microcavity structure

Abstract

This study presents the VC-BM, a novel vector bamboo joint cascaded microcavity curvature sensor, which utilizes light intensity correlation. The device is fabricated using arc fusion, connecting a tapered seven-core optical fiber with a multi-mode and hollow-core fiber. Meanwhile, mode-coupling theory optimizes its design for high-quality transmission spectra. The feasibility and sensitivity of vector curvature sensing via intensity modulation (VC-BM) have been demonstrated through theoretical simulations and experimental validation. Building upon this foundation, a novel envelope intensity differential modulation algorithm is proposed, which maintains curvature direction recognition and enhances sensitivity, reaching up to 243.57 ± 3.63 dB/m−1. Additionally, leveraging its advantages, the successful integration of a three-layer Backpropagation (BP) neural network has enabled predictive analysis of this curvature sensing device, thereby increasing its commercial value. Furthermore, the sensor's high stability and resistance to temperature interference make it an ideal solution for wearable micro-deformation monitoring.