Advances in structured light lasers

Structured light refers to light fields that are specially customized by manipulating their properties across multiple physical dimensions, demonstrating immense potential in applications such as optical communications, precision measurement, advanced imaging, and quantum information. Structured light lasers, capable of directly generating light fields with complex spatial distributions, polarization states, and topological structures, provide efficient and versatile tools for light field manipulation and its applications. Unlike structured light generation techniques that rely on external modulation, structured light lasers achieve compact and high-quality structured light output through direct intracavity control, significantly enhancing system integration and efficiency. This review summarizes the latest research progress in structured light lasers, exploring their fundamental principles, design methodologies, and applications. It introduces the basic concepts of structured light, including typical structured beams such as vortex beams, vector beams, and propagation-invariant beams, as well as more complex topological and quantum structures like optical skyrmions, non-separable states, and ray-wave duality. The review elaborates on the categories of high-dimensional structured light lasers, covering design schemes such as on-cavity structures and intracavity geometries, and provides insight into different architectures ranging from free-space and fiber-based systems to integrated devices. We also discuss the broad applications and future prospects of structured light lasers, highlighting the challenges and opportunities in this rapidly evolving field. This review aims to serve as a resource for researchers who seek to design and develop structured light lasers, as well as for those looking to harness their potential to drive innovation in photonic techniques.