On-demand micro-second switching of topological charges of DMD-generated OAM modes

We report on-demand time-resolved generation of orbital angular momentum (OAM) carrying beams with a time resolution as low as 93 μs. By loading computer-generated holograms onto Digital Micro-mirror Device (DMD) on-chip memory and by synchronously serializing the patterns, we have reliably generated OAM-carrying beams with topological charges as high as 10 with a maximum possible charge-flipping rate of 10.752 KHz. This high flipping rate is suitable to probe various atomic phenomena such as probing Rabi flopping in presence of damping, and estimating ground state decoherences using the OAM beams with this time scale. The efficiency of charge generation is enhanced by the Floyed–Steinberg error diffusion along with proper blazing and carefully choosing the beam-waist during the creation of the hologram. Fork and petal-like interferograms are obtained which account for the presence of singularity in these generated modes. This fast and reliable generation and switching of topological charges has applications in quantum communication, generation of on-demand high dimensional quantum states, and fast evolution dynamics of qubits.