Application of Neural Network Algorithms for Central Wavelength Determination of Fiber Optic Sensors

Abstract

Fiber Bragg gratings are sensitive elements in fiber optic sensor networks, and this paper discusses the practicalities of using neural network algorithms to determine their central wavelengths. The problem is to determine the central wavelength of a single sensor, the parameters of which are obtained using a low-resolution spectrum analyzer. The configuration of the neural network and the algorithm for producing the training and control datasets are specified. The training results for the selected neural network configuration demonstrated that the proposed method could determine the position of the central wavelength with a resolution two and a half orders of magnitude higher than the resolution of the input data sampling. The obtained results demonstrate that the approach makes it possible to determine the FBG central wavelength shift with an error not exceeding ~0.5 pm at a spectrum analyzer resolution of 167 pm.

Enhancing Microwave Photonic Interrogation Accuracy for Fiber-Optic Temperature Sensors via Artificial Neural Network Integration

“…by an optical frequency comb including five-seven optical spectral components in the optical part of the spectrum with a step of 5-10 GHz (40-80 pm) and full width at half height up to [30][31][32][33][34][35]. The considered wavelength range of the FPI reflection spectrum is from 1520 nm to 1595 nm.…”

“…The aim of this work is to evaluate the advantages of integrating two key technologies (microwave photonics and artificial neural networks) to solve the problems of improving the accuracy and speed of interrogation in fiber-optic measurement systems. One of the first approaches to the application of the artificial neural network apparatus in fiber-optic sensing, undertaken by the authors, was the developed algorithm for determining the central wavelength of fiber Bragg gratings as key elements of sensor networks [30]. Despite the fact that the authors obtained good results on the determination of the spectral shift of a fiber Bragg grating obtained under conditions of low spectral resolution, the work did not use microwave photonic methods, and the measurement system required a full-fledged spectrum analyzer for the wavelength range 1510-1590 nm.…”