Abstract

The existence of discrete cavity solitons (DCS) in arrays of coupled waveguides endowed with high reflecting coatings and driven by an external optical field was shown recently [1]. Stability and mobility properties of DCSs differ from their counterparts in continuous systems. But they are likewise characterized by a permanent energy exchange with their environment where their features are entirely fixed by the underlying dissipative systems. Therefore DCSs can be switched on and off at arbitrary sites of the array. That is why DCS are attractive for all-optical switching processes. Using the inclination of the holding beam as a steering parameter one can control DCS motion and location. On the other hand, the diffraction properties of discrete systems depend strongly on the inclination of the optical beam relative to the waveguides direction. The question arises: whether it is possible to find stable DCS if, for example, its angular spectrum is centered at the zero-diffraction point, close to the centre of the Brillouin zone. The existence of this so-called "midband" discrete soliton was shown for a laser with saturable absorber with a laterally modulated refractive index [2]. These "midband" solitons have a fixed inclination and can be much narrower than solitons excited at the edges of the Brillouin zone.

© 2007 IEEE