Ultranarrow beams of electromagnetic radiation in media with a Kerr nonlinearity

摘要

The vector structure of a self-channeling electromagnetic field is determined by solving the complete system of Maxwell's equations in a transparent medium with a Kerr nonlinearity. Self-channelling with an asymmetric angular distribution of the field occurs at powers several times the critical self-focusing power. As the power is increased, a universal (self-similar) field structure develops in which only the scales change as the power is varied. Self-channelling with a channel width much smaller than the (linear) wavelength of the light i.e., a "needle of light" with an extreme concentration of radiant power, is found to occur.