Our ongoing research into the formation of dark spatial solitons in self-defocusing nonlinear media has shown that bands and even a grid of stable solitary waves can exist in the cross section of a laser beam. These phenomena were observed when a wire screen was placed at the entrance face of the nonlinear medium. The creation of spatial solitons from a screen can be attributed to the large amplitude fluctuations of the diffracting beam; i.e., the high spatial frequency components are channeled into solitons. Because the solitons can propagate close to the optical axis, high resolution information that is encoded into dark solitons may be transferred over long distances without the need for large (or any) collection optics. To obtain a more thorough understanding of how dark solitons may be farmed, we placed a complex grating at the input face of a self-defocusing nonlinear medium. Such a grating may be preferred in some applications, because energy loss could be reduced.
© 1990 Optical Society of AmericaPDF Article