All-Fiber Flexible Generation of the Generalized Cylindrical Vector Beam (CVB) Over the C-Band

Abstract

We report all-fiber flexible generation of the generalized cylindrical vector beam (CVB) over the C-band, by the rotation manipulation of either polarization orientation or mode profile orientation for two linearly polarized Hermite-Gaussian (HG) modes arising in different elliptical-core few-mode fibers (E-FMFs) before their spatial superposition. By this means, the generalized CVB with arbitrary polarization rotation angle from its radial direction can be conveniently obtained. Such all-fiber flexible CVB generation is experimentally enabled by the E-FMF-based polarization controller and fiber rotator, because the effective refractive index difference between adjacent spatial modes arising in the E-FMF is enhanced. Our experimental results verify that there is almost no performance penalty over the C-band between two all-fiber rotation manipulation methods.