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.
In this work we would like to exhibit theoretical investigation of correlated fiber Bragg gratings (FBGs) for sensor applications. The spectra of FBGs have been simulated so as to overlap each other. There have been performed analysis of reflected optical power for different sensing FBGs using self-written program. Different width of scanning FBGs have been applied in order to obtain various response of sensor setup. The comparison study of these FBGs have been done. This work presents the results of simulations for reflected optical power with regard to different temperatures surrounding sensing FBGs.
This paper presents a novel, simple, low-cost and repeatable quasi-distributed optical sensor system using specially designed fibre Bragg gratings (FBGs). The main idea consists in modulation of optical power by inscribed FBGs. The optical power changes with regard to outer parameters which have an influence on dedicated FBGs. The unique configuration is provided by proper characteristics of FBGs spectra. Instead of advanced and high-cost systems we demonstrate a concept of a low-cost sensor network using specially correlated FBGs.