PROJECT TITLE :

Non-Contact Fiber Vibration Sensor Based on Intracavity Modulation of an Extrinsic Fabry–Perot Interferometer

ABSTRACT:

This paper describes a part-demodulated fiber-optic sensor appropriate for non-contact vibration detection. The sensor is based on an extrinsic Fabry-Perot (F-P) cavity, shaped by a capsulated sensor head and also the probed surface. The sensor head, bonded on a piezoelectric (PZT) stack, is driven by an eternal sinusoidal wave, which introduces section modulation in the interference signal. The varied tiny displacement induced by vibration of the surface under take a look at is detected utilizing an improved part-generated carrier technique. The configured F-P sensor is compact and highly sensitive, since neither extra optical path nor frequency modulation of sunshine source is used for demodulation. Characterization experiment is also conducted using a PZT vibration exciter. The sensor exhibits a high signal-to-noise ratio of 41 dB at 1 kHz and noise restricted detectable section level of vi.3 × 10-five rad, love a minimum vibration sensitivity of 7.eight pm.