Distributed Fiber Sensor of Temperature and Strain with mm Scale Resolution
Abstract: Distributed optical fiber sensors provide unique answers to many different sensing problems. They are now in the forefront of structural health monitoring research and are also integrated in security systems. There are a number of different methods used to implement distributed fiber sensors, each one with its own special attributes. One such method utilizes optical Brillouin scattering, an effect that is sensitive to both temperature and strain along the optical fiber. State-of-the-art commercial systems provide over 50 km of measurement range, however their spatial resolution is restricted to the order of 1 m.
Current research has been aimed at improving range, speed, sensitivity and resolution of Brillouin analysis-based fiber-optic sensor measurements. The focus of this research is on a new technique than enables, at least in principle, sub-mm resolution. Unlike all Brillouin analysis schemes known to-date, the method relies on the broadband noise that is associated with amplified spontaneous emission in optical amplifiers, instead of the modulation of narrowband laser diode sensors. This presentation will first introduce the various distributed fiber sensor technologies. Then, the new high resolution technique will be presented with the 3-4 mm resolution experimental results.
* The seminar summarizes research towards the M.Sc. degree in Electrical Engineering, carried out under the supervision of Prof. Avi Zadok.