SPECKLE PATTERNS OBTAINED IN PLASTIC OPTICAL FIBER FOR SENSING APPLICATIONS.

This paper proposes the characterization of speckle patterns of multimode fibers in view of sensing applications and particularly for detection of vibration or seismic activity. We are interested in the response to vibration by using the cylindrical piezoelectric transducer (PZT). The PZT is modulated with a frequency generator by applying a sinusoidal signal in the range of 0 to 20 Hz, so the speckle patterns can be time averaged. In this work we report the results of the characterization of 3 types of multimode fibers, with core diameters of 50 μm, 240 μm and 980 μm. [ABSTRACT FROM AUTHOR]