Light fields with extraordinary propagation behaviors, such as nondiffracting and self-bending, are useful in the optical delivery of energy, information, and even objects. A kind of helical beam is constructed here based on the caustic method. With the appropriate design, the main lobe of these helical beams can be both well-confined and almost nondiffracting, while moving along a helix with its radius, period, number of rotations, and main lobes highly adjustable. In addition, the peak intensity of the main lobe fluctuates below 15% during propagation. These promising characteristics may enable a variety of potential applications based on these beams.
© 2017 Chinese Laser PressPDF Article