The hybrid wireless and fiber optic sensor system

In this paper the hybrid wireless and fiber optic sensor system based on a fiber Bragg grating (FBG), ZigBee IEEE 802.15.4 and Radio over Fiber (RoF) has been presented. The sensor monitoring system generally consists of FBG-based temperature sensor integrating with ZigBee End Point, RoF modules and ZigBee Coordinator connected to the Managing Computer. The FBG-based sensor has been entirely demonstrated. It relies on conversion of a Bragg wavelength shift into a change of detected optical power. If the FBG spectrum is located on the spectral slope of light source, the Bragg wavelength shift implies the change of reflected optical power. Due to the distance, during the experiment ZigBee End Point and ZigBee Coordinator could not communicate. Thus, the RoF modules and single mode fiber have been applied in order to overcome the communication problems. By dint of this method information from FBG-based sensor could be transmitted to ZigBee Coordinator. Presented sensor system is easily applicable and prepared for another measurements. There are several advantages of FBG-based sensors, for instance: lightness, immunity to electromagnetic interferences or ability to long-term working. Moreover, the connection between optical fiber transmission and wireless communication ensures high flexibility and scalability. Thus, demonstrated sensor system could be applied at places with limited access.