Patent ID: 7333680

Claim:
A fiber Bragg grating sensor system comprising: a wavelength tunable laser including a wavelength tunable filter for outputting a tunable wavelength light; a first coupler for receiving the light outputted from the wavelength tunable laser and for splitting the light into two directions; a reference wavelength generating unit for receiving one of lights split by the first coupler, for generating reference wavelengths to measure real-time wavelengths of the light outputted from the wavelength tunable laser, and for defining one of the reference wavelengths as an absolute reference wavelength; a fiber Bragg grating array for receiving the other of lights split by the first coupler and for reflecting the lights by each of wavelengths of the grating therein; a fiber grating wavelength sensing unit for measuring times when each of lights reflected from the fiber Bragg grating array is detected; a signal processing unit for receiving times of the reference wavelengths generated from the reference wavelength generating unit and times when lights are detected from the fiber grating wavelength sensing unit, for calculating wavelengths in each time period of light outputted from the wavelength tunable laser, and for calculating wavelengths of the lights detected from the fiber grating wavelength sensing unit; and a laser wavelength control feedback unit for applying AC voltage to the wavelength tunable filter for output wavelength of the wavelength tunable laser to be periodically changed, and for receiving data of the wavelengths in each time period of the wavelength tunable filter from the signal processing unit and for applying DC voltage to the wavelength tunable filter in order that the wavelengths in each time period of the wavelength tunable filter are regularly repeated, wherein the DC voltage is applied in order to constantly maintain time when the absolute reference wavelength is located.