Patent ID: 7463346

Claim:
A method of measuring the birefringence of an optical fiber, the method comprising: acquiring the round-trip Jones matrix R(z) for a first interval ( 0 ,z) from a measurement starting point 0 in the optical fiber to a prescribed position z, and acquiring the round-trip Jones matrix R(z+Δz) for a second interval ( 0 ,z+Δz) from said measurement starting point 0 to a position z+Δz differing from said position z, determining the eigenvalues ρ 1 , ρ 2 of the matrix R(z+Δz)R(z) −1 , and obtaining the birefringence in the infinitesimal interval Δz from said position z to said position z+Δz by computing the following equations (1) and (2), ϕ = arg ⁡ ( ρ 1 ρ 2 ) 2 ( 1 ) Δ ⁢ ⁢ n = λ ⁢ ⁢ ϕ 2 ⁢ π · Δ ⁢ ⁢ z ( 2 ) wherein φ represents the phase difference between linear polarization components due to birefringence, Δn represents birefringence, and λ represents wavelength.