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.