Controlling the trajectory of off-axis vortices

This paper presents a novel approach for regulating the off-axis vortex trajectory embedded in a host beam. The proposed method is based on the introduction of two complex control terms into the optical field to independently modulate the linear phase gradient and the intensity distribution gradient, thereby influencing the dynamical behavior of the off-axis vortex. Through theoretical analysis, we derive the trajectory of off-axis vortices in an elliptical Gaussian background beam and reveal the control mechanism governing vortex evolution. Furthermore, by adjusting the control parameters, it is possible to effectively manipulate the motion of the off-axis vortex within a certain range, and under specific parameter conditions, even stabilize it at its initial position. We explore the applicability and effectiveness of this method through multiple case studies and experimentally validate the accuracy of the theoretical predictions.