Smart Sensor System for Detecting Temperature Changes by Polarized Light

An application in sensor systems uses, for example, changes in the polarization of light in an optical fiber during temperature changes. The principle of operation consists in the specific propagation of polarized light by special optical fibers, which, thanks to their construction, keep the light in two axes, but change the speed of their propagation and thus the instantaneous state of light polarization. It has been shown that by suitable methods it is possible to transform changes in the polarization of light into changes in its intensity, which can be detected very efficiently and quickly by a photodiode. This method has been practically verified, implemented by fiber components and confirmed as suitable for the implementation of a fiber sensor of thermal field disturbance. The aim of the work is to point out the current possibilities of using polarized light in sensor technology and for the needs of smart sensors and cities. Furthermore, the aim is to demonstrate the possibility of using a fiber sensor for thermal field disturbance as a truly feasible sensor applicable in security systems to ensure the perimeter, or in biomedical applications. In particular, analyze different ways of measuring polarization changes.