Polarization-Maintaining Optical Fibers

In ordinary axially symmetrical single-mode fibers, two mutually independent orthogonal HE11 modes can propagate. In the framework of Cartesian coordinates, these are the HE11x mode, which has its principal electric field component in the x direction, and the HE11y mode, which has principally the y component of the electric field. We hereafter omit the suffix 11 for simplicity and call these modes the HE x and HE y modes.