Study of Fiber Bragg Grating Sensor System Based on OFDR/WDM

摘要

A novel interrogating fiber grating array based on optical frequency domain reflectometry (OFDR) and wavelength division multiplexing (WDM) techniques was reported, and address inquiry of different measurement optical fiber was realized. Fundamental principle of OFDR has been analyzed and the space resolution and measurement range of this system were calculated theoretically. The calculated system's spatial resolution was 2.5m, and measurement range was 2000m. Thanks to the minimum resolution within meter range, frequency fluctuation due to trivial vibration in the environment won't cause error in the course of interrogating. Experiment studies on 3x3 fiber grating array were carried out. Experimental results confirm that with sufficiently large power of the light source, the novel fiber grating sensing array has attractive potential to interrogate and modulate several hundreds of fiber gratings in that it makes full use of optical frequency and wavelength information, and can be well applied to the distributed stress detection of two- or three- dimensional large structures.