Dual-parameter optical fiber sensor

In this paper we have presented a sensor system capable of measuring two parameters on a surface mounted beam. We have used an In-Line Fiber Etalon (ILFE) and an Intrinsic Fabry- Perot (IFP) sensor to capture two parameters at a single point. This sensor with gage length of about 200 micrometers can be used to determine the axial strain and temperature on a beam or can be embedded in composite material to determine two strain components. The two sensor signals which travel in the same fiber are discerned using coherence based multiplexing schemes. Three tests are performed with the sensor mounted on a cantilevered beam to demonstrate the concept. In the first test, the beam is subjected to simple vibration and the phase strain model is used to calculate the strains from the two sensors. In the second test the beams is given only thermal loading, and in the third test, the beam is subjected to a combination of both thermal and mechanical loading.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.