Mode and orbital angular momentum controlling of nonlocal solitons by the anisotropic diffraction

This study presents a novel approach to control the mode transform between Laguerre-Gaussian solitons and Hermite-Gaussian solitons by designing anisotropic diffraction in nonlocal medium. The anisotropic diffraction can introduce differential phase shifts and amplitude modulations to the optical field, and then leading to the transform of the soliton mode from one to another, while the accompanying orbital angular momentum exhibits a periodic variation. When the anisotropic diffraction is designed to become isotropic at the desired distance, various mode solitons with different rotation speeds and directions can be generated, which implies that the mode transform process and the change law of orbital angular momentum can be controlled. This finding establishes a versatile platform for nonlinear mode transform, offering new possibilities for applications in optical signal processing, topological photonics, optical micro-manipulation, and so on.