Nonsymmetric curved beams within a symmetric caustic skeleton.

Nonsymmetric curved beams having a symmetric caustic skeleton are presented. They arise from a finite jump in the symmetric spectral phase that breaks the symmetry of the beam intensity without altering its associated caustic curve. These nonsymmetric beams can be represented as a superposition of two caustic beams whose wave fields have well-defined even and odd symmetries with weight coefficients dependent on the phase jump. In this approach, the phase jump acts as a measure of the beam asymmetry degree that can be easily controlled in experiments. This scheme is a promising step towards optical cryptography and quantum optics applications.