Mode coupling effects in stress-applied single polarization fibers

Mode coupling effects caused by waveguide imperfections and ambient fluctuations in the stress-applied single polarization fibers have been investigated. Several origins of mode coupling, such as: 1) core deformations, 2) deformation of stress-applying parts, 3) micro-bending, and 4) temperature fluctuations, have been treated. The mode coupling parameters between the orthogonally polarized HE11modes are compared for various kinds of waveguide imperfections and ambient fluctuations. It was clarified that the deformation of the stress-applying parts is the dominant factor in the mode coupling effects in stress-applied single polarization fibers.