Study on vibration sensing performance of an equal strength cantilever beam based on an excessively tilted fiber grating

摘要

An equal strength cantilever beam vibration sensor based on an excessively tilted fiber grating (Ex-TFG) with light intensity demodulation is proposed. The basic principles and sensing characteristics of vibration sensing of an equal strength cantilever beam and Ex-TFG, the combination of which is applied into vibration sensing, are analyzed. An Ex-TFG is attached to the middle axis of an equal strength cantilever beam. As the vibration of a piezoelectric ceramic causes the equal strength cantilever beam to deform, the same and uniform deformation also occurs on the Ex-TFG. Experimental results show that when the thickness of the equal strength cantilever beam is 0.3 mm and the Ex-TFG is at transverse electric (TE) polarization state, the sensing performance is the best, with the maximum acceleration sensitivity reaching 81.065 mv center dot m(-1) center dot s(2), and the fast Fourier transform (FFT) main frequency components of the sensing signal accounting for more than 80%. In addition, this sensor is stable in sensing performance, easy in demodulation, simple in structure, high in sensitivity, and easy in manufacture, applicable for the sensing and on-line monitoring of low-frequency vibration signals. (c) 2018 Optical Society of America