Multi-ring compound fiber optic rotation measuring approach based on the Rayleigh Backscattering

A new structure of multi-ring compound fiber optic rotation velocity measurement approach was researched, in this paper, based on the single ring Rayleigh backscattering type fiber optic rotation sensing principle. N fiber optic ring cavities and N 2×2 single-mode optical fiber coupler were used in this new structure to build a model for measuring changes of scattering. The output signal of optical rotation sensor detected by optical time domain reflectometer was deduced and analyzed in digitization by MATLAB software. And then the structure parameters of the multi-ring cavity lengths and coupling ratios were optimized according to the characteristic of output signal. When the system was constructed based on the optimization simulation results in the same condition that parameters setting were N=3, range of rotate speed measure 0∼0.18rad/s and measurement accuracy 0.01rad/s, the feasibility of the system was verified by measuring the Rayleigh backscattering signal in different speed. The use of compound multiple ring cavities, compared with single ring, improved the measuring signal strength, increased the effective test data, which is helpful to identify.