Curved Bessel beams: Theory and experiments

Summary form only given. We propose a strategy to curve the trajectory of the central lobe of a zero order Bessel beam J
_o
(αr) along its propagation axis. The proposed method involves modifying the phase of the beam incident on an adaptive mirror. We show that the central lobe of the beam can be propagated along parabolic and cubic trajectories while preserving its symmetry. Theoretical simulations were reproduced in laboratory using an adjustable liquid mirror. Fig. 1 shows the parabolic trajectory of the 60 microns central spot of a J
₀
(αr) beam; it exhibits a 0.6-mm off axis shift after 30-cm propagation. The versatility of the adjustable liquid mirror allows producing other beam shapes and trajectories. For example, it is possible to split the central lobe of a Bessel beam in two (Y shape, Fig. 2); it is also possible to modify the diameter of a tunnel beam during the propagation a higher-order J
₁
(αr) Bessel beam (Fig. 3). Comparison with Airy beams and potential applications in guided-wave optics will be discussed.