Light beams carrying orbital angular momentum (OAM) have inspired various advanced applications, and such abundant practical applications in turn demand complex generation and manipulation of optical vortices. Here, we propose a multifocal graphene vortex generator, which can produce broadband angular momentum cascade containing continuous integer non-diffracting vortex modes. Our device naturally embodies a continuous spiral slit vortex generator and a zone plate, which enables the generation of high-quality continuous vortex modes with deep depths of foci. Meanwhile, the generated vortex modes can be simultaneously tuned through incident wavelength and position of the focal plane. The elegant structure of the device largely improves the design efficiency and can be fabricated by laser nanofabrication in a single step. Moreover, the outstanding property of graphene may enable new possibilities in enormous practical applications, even in some harsh environments, such as aerospace.

Recently, fundamental properties and practical applications of two-dimensional (2D) materials have attracted tremendous interest. Micro/nanostructures and functional devices in 2D materials have been fabricated by various methods. Ultrafast direct laser writing (DLW) with the advantages of rich light-matter interactions; unique three-dimensional processing capability; arbitrary-shape design flexibility; and minimized thermal effect, which enables high fabrication accuracy resolution, has been widely applied in the fabrication of 2D materials for multifunctional devices. This timely review summarizes the laser interactions with 2D materials and the advances in diverse functional photonics devices by DLW. The perspectives and challenges in designing and improving laser-fabricated 2D material photonic devices are also discussed.