Orbital angular momentum detection of vortex beam based on diffraction grating

In recent years, for the development or application of vortex beams and spatial structured optical fields, the detection of orbital angular momentum (OAM) of vortex beams has become an important topic. In this paper, based on the holographic diffraction grating method of the spatial light modulator (SLM), through a designed diffraction grating whose intensity distribution and diffraction angle are adjustable, the OAM of the single-mode vortex beam is detected. We first started with a self-designed 1D holographic diffraction grating, verified our ideas, and then designed a 2D holographic diffraction grating and successfully detected the OAM of the single-mode vortex beam. The theory and experiment are in great agreement. Our method is useful for the design of SLM-based holographic diffraction gratings and has reference value for OAM detection and data transmission systems based on vortex beams.