Optical fiber couplers: scalar supermodes and polarization corrections

Scalar field corrections of first order in weak coupling are constructed for the supermodes of couplers composed of two identical step-index optical fiber cores by a novel perturbation technique. The perturbations of the propagation constants lead to the well-known result for the scalar coupling coefficient. However, from the corrected fields the direction-dependent polarization corrections are accurately calculated for the first time, yielding accurate results for both the form birefringence, and the polarization beam splitting.<
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