Tailoring Nonlinear Processes of Orbital Angular Momentum with Dispersion Engineering in Vortex Fibers

Manipulation of nonlinear processes of orbital angular momentum (OAM) modes in optical fibers is an emerging challenge, providing the potential for a wide variety of applications in parametric amplification, high-dimensional entanglement generation, and frequency conversion. The authors demonstrate low-crosstalk intramodal processes for four-wave mixing between OAM modes in an optical-vortex fiber. By engineering the relative group velocity within a spatial dimension, the phase-matching conditions for OAM modes can be tailored. The proposed scheme may also illuminate further possibilities for generating and manipulating OAM states in fiber systems.