Tapering fiber gratings and its applications in SHM

摘要

Tapering fiber grating is a special designed fiber grating with some characters. The fiber tapering broadens the bandwidth of the grating. The strain response of the tapering gratings is somewhat different from the standard FBG. To fabricate the tapering fiber gratings, the fiber-fusing machine is utilized to pull the fiber when fiber is heated. The tapering fiber has a thin waist in the middle of the fiber to be exposed under 248nm laser. A normal phase mask is used in experiment. Because tapering process of the fiber, the bandwidth of the reflecting spectrum is broadened. There are some fabrication conditions of the tapering fiber gratings including the fusion time, loading position and exposing time. Different tapering fiber gratings have different strain response especially strain field response. A series of experiments have been done to research on the application potential of tapering fiber gratings in SHM (Structure Health Monitoring).