By investigating the nonlinear propagation of Bessel beams (BBs) in a photorefractive crystal, we demonstrate their ability to induce complex 3D waveguides with up to 9 outputs by one single diffracting BB or two counterpropagating (CP) BBs. By tuning the parameters such as the beam size, applied electric field, and input beam power, our platform enables all-optical control of output intensity levels and numbers. Besides, the spatiotemporal dynamics are investigated in the case of CP BBs, revealing the threshold value of nonlinearity for time-periodic, quasi-periodic, and turbulent dynamics with spatially localized instabilities. Finally, the continuous modulation of the orbital angular momentum is realized, and an expanded modulation range is discussed in both stationary and dynamic regimes. These results hold promise for all-optical switches, dynamical optical components, and OAM-based components for all-optical networks.
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