Fiber Bragg grating vibration-sensing system, insensitive to Bragg wavelength and employing fiber ring laser

A fiber Bragg grating (FBG) vibration-sensing system employing a fiber ring laser utilizing an FBG sensor as the ring cavity mirror was designed and developed herein. The fiber ring laser emitted lasing light at the Bragg wavelength of the FBG sensor, and the intensity of the lasing light varied with vibrations applied to the FBG sensor. Experiments demonstrated that this system could detect, with good sensitivity, vibrations over a broad band, ranging from just a few hertz up to ultrasound. This sensing system should be able to detect vibrations regardless of both the strain and temperature applied to the FBG sensor.