Nonlinear X-wave

Nonlinear X-wave schematic view

In physics, a Nonlinear X-wave (abbr. NLX) is a multi-dimensional wave which can travel without distortion.

At variance with X-waves, a Nonlinear X-wave does exist in the presence of nonlinearity, and in many cases it self-generates from a gaussian (in any direction) wave packet.

The distinctive feature of a NLX is its "biconical" shape, (see figure) which appears as an "X" in any section plain containing the wave peak and the direction of propagation.

So far, Nonlinear X-waves have been only observed in nonlinear optics experiments, and have been predicted in a variety of nonlinear media including Bose-Einstein condensates.

References and History

• Preliminary experimental results were reported CLEO/QELS conference in 2001 [1]

• The first article appeared in the arXiv:physics archive in 2002 [2]. It was later published in the Physical Review Letters: Phys. Rev. Lett. 90, 170406 (2003) [3] and reported on the theoretical prediction of the existence of nonlinear X-waves.

• The first experimental results, originally published in the arXiv:physics archive [4], appeared in the Physical Review Letters in 2003: Phys. Rev. Lett. 91, 093904 (2003)[5]