https://doi.org/10.1051/epjconf/202430910022
Low Coherence Interferometry Measurement: An Algorithm for fast processing with low noise and phase linearisation
1 INESC TEC – Institute for Systems and Computer Engineering, Technology and Science, Porto, Portugal
2 Department of Engineering Physics, Faculty of Engineering of University of Porto, Portugal
3 Faculty of Health Sciences, University Fernando Pessoa, R. Carlos da Maia 296, 4200-150 Porto, Portugal
* Corresponding author: paulo.robalinho@inesctec.pt
Published online: 31 October 2024
This work proposes a signal processing algorithm to analyse the optical signal from a Low Coherence Interferometric (LCI) system. The system uses a Mach-Zehnder (MZ) interferometer to interrogate a Fabry-Perot cavity, working as an optical sensor. This algorithm is based on the correlation and convolution operations, which allows the signal to be reconstructed based on itself, as well as, on the linearization of the signal phase, allowing the non-linearities of the actuator incorporated on the MZ interferometer to be compensated. The results show a noise reduction of 30 dB in the signal acquired. As a result, a reduction of 8.2 dB in the uncertainty of the measurement of the physical measurand is achieved. It is also demonstrated that the phase linearization made it possible to obtain a coefficient of determination (namely, R-squared) higher than 0.999.
© The Authors, published by EDP Sciences, 2024
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
