The Research Of Full Optical Fiber Current Sensor Based On Optical Fiber Ring Technology

The optical fiber current sensor is a new current sensor which has well market prospects for the next generation, the article focuses on theoretical analysis of the all-fiber current sensor and structural innovation. The work of this article is mainly in two aspects: First, in the theoretical analysis of all-fiber current sensor often uses dual light intensity to analyse the degree of polarization, so we use the Stokes vector method to analyze the evolution of the degree of polarization of the optical fiber current sensor signal. Because of the Stokes vector method have the characteristic that the transfer matrix does not exist plural, and easily reduced to a sparse matrix,what is more the final degree of polarization of the signal in a particular input conditions simply calculate the second diagonal elements of the total transfer matrix can be obtained. Because of the three advantages, the degree of difficulty to calculate and the amount of computation under certain conditions is much smaller than the traditional Jones matrix method. Second, the traditional all-fiber-optic current sensor structure is difficult to solve the problem of low sensitivity of the sensing fiber current,so a structure of an optical fiber ring cavity combined with the current sensor are proposed.The structure makes use of the sensor signal in the fiber ring through the sensor head several times,effectively improve the current sensitivity of the current sensor. Proved by experiments and theoretical that the current sensitivity of the system of the structure can be changed fluctuantly, especially when specific cycles numbers the current sensitivity can be greatly enhanced.These work has important significance for the future development of optical current sensor.