Miniaturized optical fiber displacement probe with large-collection-angle

In this paper, we propose a fiber optic displacement sensing probe based on a common optical path with a Michelson interferometer structure. The sensing model is established by integrating tilted Gaussian optical field diffraction with an optical transmission matrix, establishing a mapping relationship between the internal component parameters of the probe and the coupling efficiency as well as fringe contrast—thereby providing a theoretical basis for probe design. The proposed method enables high precision measurement of R angles and small rough spots in narrow spaces. Simulation results show that the sensing probe has a dynamic working range of 5.42–5.60 mm and an angular tolerance of ±3.84°.