Generation of arbitrary polarized OAM mode based on a fiber mode selective coupler

In this paper, the generation mechanism of arbitrary polarized orbital angular momentum mode using an all-fiber mode selective coupler (MSC), composed of a single mode fiber and a two-mode fiber, are proposed and investigated. Theoretical investigation reveals that no matter which polarization state beam is launched into the MSC, first order arbitrary polarized orbital angular momentum (OAM) mode can be obtained by carefully adjusting a squeezer polarization controller. Additionally, the excitation of first order linearly-polarized and circularly-polarized OAM modes is experimentally demonstrated when the polarization state of input light is changed.