Dye Concentrations Measurement Using Mach–Zehner Interferometer Sensor and Modeled by ANFIS

In this paper, a reliable Mach-Zehner Interferometer (MZI) dye sensor is constructed by bridging two single mode fibres (SMF₁ and SMF₂) with a short (~20 mm), tapered multimode fibre (MMF). Three MMFs with diameters of 27.7, 23.2, and 19.5 μm are tested to analyze the sensitivity of the sensor. The sensor is immersed in a Remazol Black B solution of various concentrations (40-240 ppm) where the output intensity ratio of Remazol Black B to distilled water, I_RBB/I₀, and wavelength shift, Aλ, are both recorded for each concentration. These responses are mainly dependent on the diameter of the MMF and the concentration of the RBB dye solution. Response surface methodology is utilized to evaluate the interactions of few parameters simultaneously as well as to interpret the obtained results in statistic form. Furthermore, a modeling approach, adaptive neurofuzzy interference system is deployed to construct two empirical models with the given responses from the sensor, hence predicting the concentration of the RBB solution. The squared correlation coefficient (R²) between experimental and predicted results, mean absolute percentage error, and root mean square error is calculated to measure the accuracy of the models developed in the study. Finally, an additional experiment is conducted to validate the accuracy of the predictive models and the results obtained are encouraging.