Investigation of optical fiber vibration sensor based on cantilever length continuously tunable technology

Abstract In this paper, an optical fiber vibration sensor with a tunable sensitivity and frequency response range is proposed for the first time, in which a cantilever length adjustable structure based on a sliding pedestal is employed to adjust the response performance of a single mode-multimode-single mode (SMS) based optical fiber vibration sensor. Firstly, the influence of the cantilever length on the frequency response range and the sensitivity of the SMS vibration sensor are investigated theoretically. On this basis, experiments are carried out to investigate the effectiveness of the proposed scheme for the adjustment of sensor response, and the experimental results demonstrate that the flat frequency response range of the proposed sensor can be extended from 200 Hz to 400 Hz with a decreasing sensitivity from 500 mV g − 1 to 160 mV g − 1 by tuning the vibration length of the cantilever beam from 2.8 cm to 2.0 cm through a sliding pedestal. The results also indicate that a response linearity of 99% and a signal-to-noise ratio around 43 dB within the whole flat frequency response range can be achieved during the tuning process, which confirms the feasibility of the proposed scheme for the performance optimization of vibration sensors, which provides a flexible and cost-effective approach to improve the applicability of cantilever-based optical fiber vibration sensors to various situations.