Patent Document ID: 9841349
Application ID: 15382671
Patent Flag: 1

Claim One:
1. A method for distributedly measuring polarization transmission matrices of an optical fiber, comprising steps of: inputting a fully polarized pulse into the optical fiber with linear birefringence only; and demodulating polarization states of Rayleigh backscattered light at different points on the optical fiber from a pulse input end; after demodulating, dividing the polarization states of the Rayleigh backscattered light into Q groups in sequence, wherein every three polarization states are divided into one group; calculating the transmission matrix of Group N, defining polarization transmission matrices corresponding to a segment from (3N−3)Δz to (3N−2)Δz, a segment from (3N−2)Δz to (3N−1)Δz, and a segment from (3N−1)Δz to (3N)Δz as M 3N-2 , M 3N-1 and M 3N , wherein due to slow changes of principle polarization axes of the optical fiber, M 3N-2 =M 3N-1 =M 3N =M x (N), so that M x (N) is the transmission matrix of the Group N; wherein, Δz is a pulse width, N is a positive integer from 1 to Q; and listing an equation set: { S B 0 ⁡ ( 3 ⁢ N - 2 ) = M A · M x 2 ⁡ ( N ) · M A · S i ⁢ ⁢ n S B 0 ⁡ ( 3 ⁢ N - 1 ) = M A · M x 4 ⁡ ( N ) · M A · S i ⁢ ⁢ n S B 0 ⁡ ( 3 ⁢ N ) = M A · M x 6 ⁡ ( N ) · M A · S i ⁢ ⁢ n wherein in the equation set: 
 M A =M 3N-3 ·M 3N-4. .. M 2 ·M 1 =M x 3 ( N− 1). .. M x 3 (1); s in is a polarization state of an input lightwave; S B 0 (3N−2) is a polarization state backscattered from a point (3N−2) Δz and received at the point 0; S B 0 (3N−1) is a polarization state backscattered from a point (3N−1) Δz and received at the point 0; S B 0 (3N) is a polarization state backscattered from a point (3N) Δz and received at the point 0; and solving the equation set using a numerical analysis method in order to obtain multiple solutions, and screening the multiple solutions according to the characteristics of the polarization transmission matrix, wherein each time of screening provides a unique solution M x (N) of the equation set; continually updating M A values for iteration, so as to obtain the distribution of polarization transmission matrices of the optical fiber, which is a series of polarization transmission matrices corresponding to each pulse width of the optical fiber.