Interrogation a Fiber Bragg Grating vibration sensor by narrow line width light

A method to interrogate fibre Bragg grating vibration sensor by narrow line width light is demonstrated; the interrogation scheme takes advantage of the intensity modulation of narrow spectral bandwidth light, such as distributed feedback laser, when a reflection or transmission spectrum curve of an FBG moves due to the strain which applied on the sensor. The sensor's response to acceleration frequency and amplitude is measured by experiment. We also discussed the factors which have impacts on the sensitivity of the interrogation system.