Laser cavity creation of one or dual orbital angular momentum vortex beams by edge diffraction regulation

Abstract

In the past three decades, a unique beam called vortex beam with orbital angular momentum has become the research focus of researchers. However, to date, almost all the methods for generating vortex beams are to adjust the phase distribution of the central part of the beam cross section. Is there a method to generate high-purity one or dual orbital angular momentum vortex beams based on the edge diffraction regulation? Specifically, it has been shown that a variety of complex laser modes can be generated in a special laser cavity, and these modes are difficult to control. How to create vortex beams from these complex patterns is an important scientific problem. This paper solves this scientific problem based on edge diffraction regulation in laser cavities. Only three variable aperture diaphragms are needed to realize the generation of one or dual orbital angular momentum vortex beams. Moreover, the topological charge of the beam is proved by interference experiments. This work can not only break the understanding of traditional vortex beam generation method and deepen the understanding of laser cavity regulation technology but also bring opportunities for optics, electromagnetics, and other related fields.