Caustic optical beams arising from a spectral phase whose power lies in an unusual range of values less than two are presented. Unlike what happens for conventional phase powers greater than two, it is feasible to generate ...

A controllable manipulation of the energy distribution of caustic beams possessing rectangular symmetry is presented. The beams are designed from the spectral phase by adding a linear and/or quadratic perturbation having ...

Needle-like electromagnetic field has various advantages for the applications in high-resolution imaging, Raman spectroscopy, as well as long-distance optical transportation. The realization of such field often requires ...