EDM Studio Inc. - Solitons

Over 150 years ago, the naval engineer J. Scott-Russell witnessed something peculiar on a Scottish canal, a foot-high bow wave from a stopping boat that instead of quickly dissipating, preserved its shape and continued along for more than two miles. Scott-Russell had observed a soliton, a localized nonlinear wave with striking stability properties.

To the naked eye, this beam (represented by the solid blue/cyan curves) is constant. Internally, however, many components oscillate back and forth in perfect balance - trapped by their self-induced wave-guide.

Solitons have since been observed in many physical systems. In optics, they have been studied extensively as possible information carriers in next generation telecommunication systems.

In a fiber-optic link, the beam's natural tendency to expand sideways is prevented by the cladding of the cable. This material, with an "index of refraction" lower than the glass core, gently steers the travelling pulse, keeping the energy contained and heading towards its destination. The fiber-optic cable acts as a so-called "wave guide".

Rather than a cladding, researchers have been studying materials whose refractive properties are modified by the beam itself. For carefully crafted input beams, a self-induced wave-guide can form in an otherwise uniform medium. Such a beam is known as a spatial soliton.

In the numerical experiment shown at right, a spatial soliton (an unchanging robust light beam) is formed from thousands of incoherent components. While the individual components oscillate back and forth, the sum total is a constant - and to the eye, unchanging - beam.