In this work, we propose a polarization-maintaining, weakly coupled few-mode fiber with a uniform doping concentration, designed via a particle swarm optimization algorithm and a discrete point configuration method. The design features a circular central air hole and an irregular doped boundary. Across the C+L band, all 14 modes exhibit an effective refractive index difference exceeding 1.43×10−4. Compared to conventional polarization-maintaining few-mode fibers, the proposed design offers enhanced flexibility, ensuring mode isolation with a very non-complicated process. This approach can be readily extended to other inhomogeneous optical waveguides, offering a valuable framework for intelligent design in non-uniform waveguide systems.
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