WAVEMETER OF OPTICAL SIGNAL, FIBER BRAGG GRATING SENSOR AND METHOD THEREOF USING WAVE SELECTION TYPE OPTICAL DETECTOR

摘要

PURPOSE: A wave meter of optical signal, a sensor of fiber bragg grating(FBG) and its method are provided to measure a wavelength change of a reflective light caused by a perturbation such as a temperature and a strain fed to the FBG using a wave dependence of a wave selection typed optical detector. CONSTITUTION: An optical signal emerged from a source of light(41) having a broadband spectrum width such as an ASE(Amplified Spontaneous Emission) noise of an LED(Light Emitting Diode), an SLD(Super Luminescence Laser Diode), or an EDFA(Erbium-doped Fiber Amplifier) is projected into a FBG(43) through an optical coupler(42) and a reflective light of narrow band fit for a condition of the FBG(43) is transferred to the other optical coupler(44) by diverging in the optical coupler(42). The optical coupler(44) distributes the reflective light to a usual optical detector(45) and a wavelength selection type optical detector(46), and the usual optical detector(45) and the wavelength selection type optical detector(46) converts the diverged optical signal to an electric signal. The signal converted to the electric signal is amplified, differentially amplified and divided in a processor of signal(47) and the amount of parameter fed in the FBG(43) is measured by referring to a lookup table corresponding to a stored changed amount of wave and a sensing parameter.