MATHEMATICAL JUSTIFICATION OF FIBER SENSORS BASED ON FIBER BRAGG GRATINGS

Abstract

Nowadays, the most promising approach is the use of fiber-optic sensors as a key element of the monitoring system. Fiber-optic sensors (FOS) have a number of advantages, the most important of which include immunity to electromagnetic interference, low weight and the possibility of their inclusion in the measured structure. The use of such sensors in the monitoring system will make it possible to simplify the measurement and obtain reliable data, as well as to obtain all new possibilities for measuring various quantities simultaneously.The most perspective are the sensors based on the Bragg fiber gratings. Bragg fiber gratings have several advantages, for instance, they allow creating the distributed measuring massifs, which contain several sensors. As well, they are insensitive to the optic power source vibrations. Variety of using the fiber sensors based on the Bragg fiber gratings has led to producing the Bragg fiber gratings with different spectral characteristics.The article herein considers the issues of the Bragg fiber gratings mathematical modeling using the transfer matrix method. Transfer matrix method allows defining the optical components spectral characteristics based on the bound modes theory and description of electromagnetic wave, passing through an optic fiber. In the article there have been analyzed the Bragg fiber gratings in compliance with spectral features, such as transmission and reflectance spectra.