Evaluation of polarization mode coupling coefficient from measurement of polarization mode dispersion

Abstract

Polarization mode coupling coefficient is evaluated from the measurement of polarization mode dispersion as a function of fiber length in a single-mode fiber having an elliptical-core with 10-percent ellipticity. The modal dispersion measurement are carried out by the improved spatial technique based on an optical heterodyne detection at the wavelengths of 0.85 and 1.3 μm. The coupling coefficients are evaluated from the measurements to be <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3.4 \times 10^{-3}</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4.6 \times 10^{-3}</tex> m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> for modal-birefringence magnitudes of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8 \times 10^{-6}</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3 \times 10^{-6}</tex> , respectively. The coupling coefficients obtained from the dispersion measurement are coincident with those evaluated from the extinction-ratio measurements. In addition, dependence of the coupling coefficient on propagation constant difference between the two orthogonally polarized HE <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf> modes is investigated based on Lorentzian power spectrum model.