High-precision data analysis for TFBG-assisted refractometer

[Display omitted] •A new signal-processing method for TFBG-assisted refractometer is presented•The method’s efficiency in a wide dynamic range is demonstrated by experiments•The provided resolution of refractive index measurements is 5.2 × 10−5 RIU The paper is devoted to the tilted fiber Bragg grating (TFBG)-assisted fiber refractometer. A novel mathematical method for the automatic analysis of its signal is proposed. A change in the refractive index is associated with a change in the cut-off wavelength, which is determined from the envelopes of the sensor’s transmission spectrum. Distinctive features of the proposed approach include its simplicity and high measurement accuracy. The implementation of the proposed mathematical apparatus resulted in the resolution of the sensor being calculated as 5 × 10−5 RIU, according to the experimental results. In this case, the measurements were carried out in a fully automatic mode. The proposed approach opens up prospects for the application of fiber refractometers in physics, chemistry, and medicine.