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Updated: Jul 7, 2026
Fabrication of a Low-Cost, Fiber-Coupled, and Air-Spaced Fabry-Pérot Etalon
Published on: February 3, 2023
High-resolution interrogation technique for fiber optic extrinsic Fabry-Perot interferometric sensors by the
1Department of Optical Engineering, School of Information Science and Technology, Beijing Institute of Technology, Beijing 100081, China. bitjy@bit.edu.cn
Abstract:
An improved peak-to-peak method is developed for interrogating the absolute cavity length of fiber optic extrinsic Fabry-Perot interferometric (EFPI) sensors with high resolution. A fiber Fabry-Perot tunable filter (FFP-TF) is used to scan the optical spectrum of an EFPI, and the problems caused by the nonlinear performance and poor repeatability of the FFP-TF are removed by using a wavelength calibration technique. A linear fitting is used to calculate the wavelength spacing between two adjacent apexes in the optical spectrum, and the cavity length can be retrieved using this wavelength spacing. The experimental results show that the measuring resolution is improved from 25 to 1 microm, and a linear output is also obtained.
