Microvibrating fiber-optic sensors

The principle of vibration sensors is to measure the shift of a resonance frequency caused by changes in the environment. Amplitude and frequency equations for a fiber-optic cantilever vibrating under the action of modulated laser radiation are analyzed. The possibility of a considerable increase in the sensitivity of a sensor is considered on the basis of Q-factor analysis and optimization. Fiber-optic Bragg grating allows the detection and measurement of vibrations. This grating should be located on the tip end of a vibrating fiber cantilever. Analysis of the nonuniform increase in the length along a vibrating fiber cantilever makes it possible to calculate changes in the reflection spectrum of the grating.