Perimeter System Based on a Combination of a Mach-Zehnder Interferometer and the Bragg Gratings

• Main Authors: Marcel Fajkus, Jan Nedoma, Petr Siska, Lukas Bednarek, Stanislav Zabka, Vladimir Vasinek
• Format: Article
• Language: English
• Published: VSB-Technical University of Ostrava 2016-01-01
• Series: Advances in Electrical and Electronic Engineering
• Subjects: bragg gratings; mach-zehnder interferometer; monitoring of movement; perimeter system.
• Online Access: http://advances.utc.sk/index.php/AEEE/article/view/1752

Fiber optic interferometers and Bragg gratings belong to the group of very precise and sensitive devicesthat allow measuring very small deformation, temperature or vibration changes. The described methodology presentsthe useof a Mach-Zehnder interferometer and Bragg gratings together as a sensor system for detecting and monitoring movement within thedefined perimeter of 2.5×1m. Analyses of the dynamic changes in interferometric patterns were a basis for this method. Also the signal maximum amplitude was measured and compared with the noise background. Perimeter disruptions can be detected by Bragg gratings due to its large deformation sensitivity in transversal or perpendicular directions. The result is then evaluated in the spectral domain. In terms of detected persons it showed very good results. The combination of these sensors was chosen for monitoring both the static and dynamic phenomena. Author's aim is to take advantage of both devices' positive properties. Thus, the system has the abilityto identify people due to frequency analysis in case of interferometers as well as dynamic weighting thanks to Bragg gratings.