High-Sensitivity and Large-Range Displacement Sensor Based on a Balloon-Shaped Optical Fiber and Machine Learning Analysis

The concurrent attainment of high sensitivity and a large dynamic range in measuring parameters of interest holds paramount importance in sensor development. In this paper, we demonstrate a displacement sensor based on a simple balloon-shaped optical fiber device that boasts both high sensitivity and a broad dynamic range, empowered by machine learning (ML) analysis. This ML-driven approach capitalizes on global features extracted from the measured raw spectrum, overcoming the constrained dynamic range limitations posed by the traditional dip tracking method. A root mean squared error as low as 0.193 mu m is obtained within a displacement calibration range of 0 similar to 300 mu m, despite utilizing a modest training dataset. The reliable prediction of unseen displacement within the calibration range is also demonstrated. This intelligent sensor system, combining a straightforward balloon-shaped fiber device with ML analysis, holds promise for wide-ranging, high-precision displacement sensing applications across diverse fields.