Interferometeroppstilling for implementering av serielle fiber Bragg gitterinterferometeroppstillinger, og optisk fibersystem som benytter denne

摘要

An interferometer array includes a plurality of interferometer sub-arrays, each sub-array including a plurality of interferometers. Each interferometer in a sub-array is implemented with a respective pair of fiber Bragg gratings and a sensing length of optical fiber positioned between the respective pair of fiber Bragg gratings. The fiber Bragg gratings in each respective pair of fiber Bragg gratings have the same characteristic wavelength that is different from the characteristic wavelength of every other pair of fiber Bragg gratings in the sub-array. The sub-arrays are interconnected to minimize the common-wavelength crosstalk between the sensors in the overall interferometer array. In one embodiment, the sub-arrays are connected in series along a common length of optical fiber such that the maximum common-wavelength crosstalk is limited by the number of sub-arrays connected in series. In a second embodiment of the invention, branches are interconnected to a common input/output optical fiber via optical couplers, and each branch has one or more sub-arrays connected in series. The common-wavelength crosstalk is limited by the number of arrays in each sub-array. In a third embodiment of the invention, branches are interconnected between an input optical fiber and an output optical fiber via optical couplers, and each branch has one or more sub-arrays connected in series. Optical signal delay elements are positioned in the input optical fiber to incrementally increase the delay experienced by an input optical signal before it reaches each successive branch connected to the input optical fiber. Therefore, the return optical signals from each sub-array in a branch are separated in time from the return optical signals from the sub-arrays in the other branches.