Spatial solitons extend depth of focus

Researchers at the Italian National Institute of Materials Physics and the University of Insubrio (both in Como, Italy) have shown how the second-order nonlinearity in some crystals can be exploited to extend the beam waist of a focused image based on formation of spatial solitons.¹ So far, depth of focus has been increased 3.6 times, and experiments have begun to reveal some of the differences between single- and multiple-soliton propagation. This kind of technique could eventually be exploited in devices for all-optical processing. Such devices are particularly needed in the field of communications, in which engineers are trying to find their way around the bottleneck of photonic-electronic interfaces.