Generation of optical Bessel beams with arbitrarily curved trajectories using a magnetic-liquid deformable mirror.

We propose a new strategy to curve the trajectory of the central lobe of a zero-order Bessel beam and a first-order Bessel beam along their propagation axis. Our method involves modifying the phase of a beam that is incident on an adaptive mirror. As examples, we show that the most intense lobe of the beam can follow a parabolic trajectory, a cubic trajectory, or a trajectory made by a combination of these orders. By using a phase correction emulating the effect of cylindrical mirrors, the central lobe always preserves its symmetry. Theoretical simulations were reproduced in the laboratory using a magnetic-liquid deformable mirror. The parabolic trajectory of the 60-μm central spot of a zero-order Bessel beam exhibits a 0.6-mm off-axis shift after 30-cm-length propagation.