The identical weak reflection Fiber Bragg gratings(FBGs) with large capacity has become one of the central issues of optical fiber sensing field in the engineering application. Currently, wavelength division multiplexing(WDM) and time division multiplexing(TDM) are two major multiplexing techniques. For a WDM system, the maximum number of FBGs is limited by the spectral bandwidth of laser. So the identical weak FBGs are proposed to break through the limitation of the multiplexing capacity. For large-capacit...